Nlewslerrcr July 1995 No.37 2Toocopies
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NlewsLErrcR July 1995 No.37 2Toocopies Editor-in-Chief: Gerhard Chroust c/o Systemtechnik und Automation, Johannes Kepler University Linz, 4040 LinlAustria, e-mai I : CH ROU ST @ S EA. IJN I -Ll NZ.AC.AT, Tel :+43-7 32-2468-865, Fax:+43-732-2468-878 Dear fo:aders! Again I fiaoe to apobgize for a [etay in tfik fuftus[ettet I fiaae 6een interciae{y irno[tte[ in 6otfi tfu Conference an[ tfuEuropean'ESlPltl yrojut (see bsi[e) . I ang[a[ to report tfrat part of tfu tast grQus[etter (fu.36) uas snrcessfu[[y pinte[ in tfu '[1SA an[ [istributel frotn tfure. It saoes manE an[ sfiouf[ ena6[e a prompter le[iaery of tfu fousbtter to our or)erseas members. eart of tfu leky of tfu fiQustetter b a[so fiu to tfie aery sbw subntission oJ topics suitab[e for 'fiQu Trends', Iftis issue's 'furu'Trenls' are conceraed tuitfi a aery interuting EUROCAST on the Rocks proS[em in autonomous ro1otics. Wfun I started tfu '9@u From left to right: Trends' afumn I fiopel to preseflt a ztieu of ruear& Prof. Sato, Japan, Prof. Pichler, Austria, Prof. [irectioru tfiat is as 6roal as possi6k. Anforatnatety I fiaae Takahara, Japan, Prof. Candela-Sola, Spain. rut rueioel many suitaS[e submissbtu. Q[ease re-meru\er trtat EUROCAST'gs. I am ahtays boftng for interatitrg antri|utiors fo, 'fuu trends'. Is your subjut nat wortfiy to 6e presentel? sth lnt. Workshop on Computer Aided I uou[d ogoin remind you tfiat tfu nQusb*er (an[ some Systems Technology (CAST) otfur interating pieus oJ infornation are aaaikSfe ofl May 22-25, 1 995, lnnsbruck, Austria IFSKI 'WW,l-pagu,'Lfu outss is aia tfu A\L @niform fosource Locator) The Fifth lnternational Conference on Computer place the fittp : / / unwtt.s e a. uni- finz. ac. at / fs I Aided Systems Technology took at finatty I uou[[ tifo to uisfi you a p[eosant fio[i[ay *ason Conference Center of lnnsbruck in Tyrol / Austria and fiope to fuarfromyou in Sepaniel f rom May 22 - 25, 1995, under co-sponsorship of IFSR. Qerfinrd Cfuoust Sy s tcmtufinifr unf Automation More than 100 scientists from about 20 countries lofiaraus ftp[er'tlniaersial Linz, 4040 Lita, Austrin including US and Japan coming from Universities and lndustries discussing new results in the area of Systems Theory, Systems I contri.6 utbn ! fSKuan* /our Engineering, Design Science and Computer We are interested to an et)en estefi-t in naftng tfie treater Science and its application to important fields l&ws{etter a infornation intercfiange. We forum for such as Engineering (lnformation Systems, tfurefore asfr you to senl us sfiort rEorts on refeaant Signal Processing, Control, Robotics and others) anferenccs/mutittgs, aflnoun&fiicnts of cnnferenus or Ecology, Management and Sociology. The main rettiews of interuting 6oofu. can reacfi us 6y mait, /ou Ja4 goal of the conference is the provision of e-mai[. E-maif suimissioru are preferred! promise a 'lile fairQ computerized tools for modelling on systems s fio rt turn- aro ufl[ tifie !, level. IMPRESSUM: Mediuminhaber, Herausgeber, Satz und Professional highlights were the invited lectures Layout: Int. Federation for Systems Research. by Prof. G. Gottlob, Vienna, on "Reactive Logic: Fiir den Inhalt verantwortlich: Prof. G. Chroust, Iohannes Approaches ro Knowledge Base Revision and Kepler Universitiit Linz. 4040 Linz, Druck: Druckerei Bad Update", Prof. S. Rinaldi, ltaly, on "Chaos and Leonfelden Ges.mb.H. & Co. KG, Bad Leonfelden. Complexity" and Prof. W. Wymore, USA, on "Systems Engineering, Systems Theory and Complex Systems". The social programme offered a trip by cable-way to the mountain-area of the Hafelekar where more than 50 people Eurocast '97 is planned again for Las Palmas, assembled happily for an informal gathering on Canary lslands, Spain, in February 1997. the high sealevel attitude of about 2.334 m. NEW TRENDS lrurecnerED NAvrcATtoN Sysrena FoR Low-Gosr MoetLe Roeors Rudolf Bauer Siemens AG, Corporate Research and Development, 81730 Milnchen, Germany email : Rudolf . Baue r @ zfe.sie mens. de defined mission, localization and map building) Introduction uses a three-layer system consisting of For a mobile robot operating autonomously in an unknown, unprepared environment it is essential . "Global (position Path Planning": Based on the user's to know its configuration and mission and a global on-line grid map of the orientation) while executing a user defined environment, a very fast geometrical global mission. rough estimation robot's A of the path planner produces a "rough" path configuration possible data is with odometric consisting of a set of intermediate goal points. (speed path length), to and but due . "lntegrated Path Planning": The global path is unpredictable slippage of the wheels and other used, together with information about the physical imprecisions, estimated the current landmark map, the robot configuration configuration deteriorates large due to a and its uncertainty and local obstacles, to cumulative error. To reduce the uncertainty and plan a more detailed local path. error, localization techniques additionally are . and "Robust Obstacle Avoidance": This local based on sensor data (e.9. sonar) and a gradual path is then sent to the robot's pilot level, development of a map of the environment. The which autonomously executes the path, while resultant configuration error mainly depends on guaranteeing robust obstacle avoidance. the amount and quality of the incoming sensor Each of the layers uses a limited level of know- data. The quality these critically of data is ledge of the robot environment, thus acting with dependant on the path chosen by the robot. well-defined competence and responsibility. A novel dynamic and integrated path planning Suitable ldyer interaction provided by an approach is used to concurrently support the intelligent scheduler leads to the desired data acquisition for estimating the location and behavior of the overall system. identifying new natural landmarks in an a-priori unknown environment. This creates the following While executing the path, the behavior of boot-strapping problem. update and To important system states (e.9. configuration continuously correct its configuration, the robot uncertainty) is monitored. ln the case of needs an adequate landmark map. On the other considerable deviations, which might occur in an hand the robot needs to know its configuration a-priori unknown and dynamic environment, the very accurately so as to identify old and new execution is stopped and the integrated land-marks. This process may become unstable navigation scheduler is informed, which might if the robot travels in a way by which its sensors then restart the cycle. cannot adequately recognize previously identified landmarks. Therefore, a compromise Experiments must be found between keeping the The following experiments were performed on configuration uncertainty low, identifying new the Siemens mobile platform Roamer (Robust landmarks and fulfilling a user defined mission. Autonomous Mobile Experimental Robot). lt has 24 Polaroid lntegrated Navigation System ultrasonic sensors that are arranged in two horizontal layers around the robot. A general hierarchical architecture for mediating between different robot goals (fulfilling a user ln both simulated test runs (see Fig. 1 and 2), landmarks the angular visibility range is indicated the robot had no a-priori knowledge of it's in Fig. 2). Arriving at target point B the robot had workspace other than the gray shaded an absolute positional error of just about '15 cm rectangular outline of the workspace and two afler 25 m of traveled distance. - linetype landmarks (a, b) at the starting point A. " '. '',1 -*. .B A Fig. 1: Traveling directly from A towards B with Fig. 2: Traveling from A to B, using identified reactive obstacle avoidance. The mission was intermediate landmarks interrupted because of the significant configuration uncertainty. This approach dynamically plans local paths, in "user Because the robot has no knowledge of the order to integrate the different robot tasks "self-localization" "land- obstacles in its workspace (see Fig. 1), the robot defined mission", and estimated starts to travel from A directly towards the target mark building" by analyzing the point B. After a few meters the first obstacle benefits and costs ol each. comes "in sight" which is avoided by moving to Bauer, R. et al. (1994). Steer Angle Fields: An the right. After leaving the visibility regions of the Approach to Robust Maneuvering in Cluttered, given landmarks a and b, the configuration Unknown Environments, Robotics and Autonomous grows motion uncertainty dramatically. During Systems, vol. 1 2, pp. 209-212, 1994. the configuration uncertainty grows rapidly due Bauer, R. (1995). Dynamic Path Planning lntegrating to an assumed 5% slippage of the wheels Self-Localisation and Landmark Extraction, Proc. of Using the novel approach (Fig. 2) of integrated IAS-4: lnt. Conf. on lntelligent Autonomous path planning, the robot mediates between three Systems, pp. 42O-426, Karlsruhe, 1995. subtasks: Bauer, R. and Rencken, W.D. (1995). Sonar Feature . - traveltowards point B, Based Exploration, to appear in: IEEE/IRJ Conf. on 5-9, . - keep configuration uncertainty low, lntelligent Robots and Sysfems, Aug. - identify new landmarks Pittsburgh, 1995. ln Fig.2 the robot has found a number of natural landmarks, that are concurrently used to improve the configuration estimate (For point type The systems sciences appear to have three Pno.lecr Rrponrs interrelated tasks: discerning of the integrative "wisdom" stored in biological organisms after several billion years of evolution; integrating Some pathways to integrative knowledge and understanding; applying the study, education, and thought insights obtained to problems of human and Joseph Engelberg ecological existence. The approach is necessarily integrative rather than disciplinary or UHrvensrv oF KENTucKY, CoLLEGE oF inter-disciplinary, interdisciplinarity being taken to MeordNe, LExtNGToN, Kerurucxv 40536-0084, limit disciplines become invisible, USA. the so that the not even referred to.