Multi-Robot Motion Planning: Theory and Practice

Total Page:16

File Type:pdf, Size:1020Kb

Multi-Robot Motion Planning: Theory and Practice The Raymond and Beverly Sackler Faculty of Exact Sciences The Blavatnik School of Computer Science Multi-Robot Motion Planning: Theory and Practice Dissertation submitted in partial fulfillment of the requirements for the degree of \doctor in philosophy" in the School of Computer Science, Tel-Aviv University by Kiril Solovey This work has been carried out under the supervision of Prof. Dan Halperin March 2018 Acknowledgments I wish to express my endless gratitude to my advisor Prof. Dan Halperin. I had a great privilege to work with this kind, smart, professional, generous, and inspiring person. I thank him for instilling in me the passion for science, learning, and exploring the unknown. I would like to thank my dear friends and lab mates Michal Kleinbort, Oren Salzman, and Omri Perez, with whom I've had memorable moments, and who made my time at the lab extremely enjoyable. I also wish to thank all the members of the applied computational geometry group over the years and the algorithmic game theory group for their companionship. I also thank the administrative staff of the School of Computer Science, Tel Aviv University, and especially Gilit Zohar-Oren, Pnina Neria Barzilay, Larisa Slepyan-Eshed, Anat Amirav, and Mika Shahar. I wish to thank my parents for being remarkably supportive throughout my life and especially so for my years in academia. The last person I thank is my partner Nadia, without whom this life would have been mostly a dull journey through space. I would also like to thank the Clore Israel Foundation for supporting me during my Ph.D. studies. My work has also been supported in part by the Israel Science Foundation (grants nos. 1102/11 and 825/15), by the Blavatnik Computer Science Research Fund, and by the Blavatnik Interdisciplinary Cyber Research Center at Tel Aviv University. Thank you all, Kiril Preface This thesis presents a collection of seven published papers that were prepared during my Ph.D. studies. It consists of three journal publications and five peer-reviewed conference publications (see below). Journal Publications Kiril Solovey and Dan Halperin, \On the Hardness of Unlabeled Multi-Robot Motion Planning." • Special issue (invited), International Journal of Robotics Research, 35(14): 1750{1759, 2016. Also in Robotics: Science and Systems, finalist for best paper, and winner of best student paper, 2015. Kiril Solovey, Oren Salzman and Dan Halperin, \Finding a Needle in an Exponential Haystack: • Discrete RRT for Exploration of Implicit Roadmaps in Multi-Robot Motion Planning." Special issue (invited), International Journal of Robotics Research, 35(5): 501{513, 2016. Also in Workshop on Algorithmic Foundations of Robotics, 2014. Aviv Adler, Mark de Berg, Dan Halperin and Kiril Solovey (alphabetical order), “Efficient • Multi-Robot Motion Planning for Unlabeled Discs in Simple Polygons." Special issue (invited), Transactions on Automation Science and Engineering, 12(4): 1309{1317, 2015. Also in Workshop on Algorithmic Foundations of Robotics, 2014. Conference Publications Kiril Solovey and Michal Kleinbort, \The Critical Radius in Sampling-based Motion Planning" • In Robotics: Science and Systems, Carnegie Mellon University, Pittsburgh, PA, USA, 2018. Kiril Solovey and Dan Halperin, “Efficient Sampling-based Bottleneck Pathfinding over Cost • Maps." In International Conference on Intelligent Robots and Systems, Vancouver, BC, Canada, 2017. Kiril Solovey and Dan Halperin, \Asymptotically-Optimal Bottleneck Pathfinding with Applica- • tions to Fr´echet-Type Optimization." In European Symposium on Algorithms, 76:1{76:16, Aarhus, Denmark, 2016. Kiril Solovey, Oren Salzman and Dan Halperin, \New Perspective on Sampling-based Motion • Planning via Random Geometric Graphs." In Robotics: Science and Systems, University of Michi- gan, MI, USA, 2016. Kiril Solovey, Jingjin Yu, Or Zamir and Dan Halperin, \Motion Planning for Unlabeled Discs • with Optimality Guarantees." In Robotics: Science and Systems, Sapienza University of Rome, Italy, 2015. Abstract Motion planning is a fundamental problem in robotics concerned with allowing autonomous robots to efficiently navigate in environments cluttered with obstacles. Although motion planning was initially studied as a theoretical problem in computer science, it is applied nowadays in various fields such as computational biology, computer graphics, and most naturally robotics. Unfortunately, motion planning is notoriously challenging|both theoretically and practically|and many aspects of the problem are not sufficiently understood, even after 30 years of extensive multidisciplinary research. Perhaps the most challenging aspect of motion planning is the complex and the high-dimensional search space that it induces, which accounts for the geometric structure of the robot, the physical constraints that it needs to satisfy, and the environment in which it operates. This thesis is mainly devoted to the study of theoretical and practical issues of high-dimensional systems consisting of multiple robots. In particular, we consider multi-robot motion planning (MRMP), which is a natural extension of motion planning concerned with the collision-free coordination of multiple robots operating in a shared environment. We present a theoretical hardness result concerning MRMP, which applies to several variations of the problem, including the unlabeled setting which consists of identical and interchangeable robots. We show that it also applies in the standard labeled case. This is the strongest MRMP hardness result in that it pertains to the simplest possible robots over previous proofs: unit squares. We then show that by making relatively-mild simplifying assumptions on the problem one can drastically reduce its complexity. In particular, we consider two settings with such assumptions and devise algorithms that run in time that is (low-)polynomial both in the number of robots and the complexity of the environment. Notably, one of the approaches even comes up with solutions whose cost, i.e., the total length the robots traverse, is (theoretically) close to the optimum. We also consider a sampling-based approach for MRMP and present a new algorithm, which applies to more general settings of the problem, and outperforms the best previously known solutions in practice. The second part of the thesis is devoted to the study of sampling-based planners, with emphasis on their theoretical guarantees. In particular, we present a general approach to analyze such algorithms by establishing a novel connection to the a well-studied mathematical subject of random geometric graphs. We then present two papers that are devoted to sampling-based motion planning under bottleneck cost, which had only been lightly treated before them in the literature, despite its importance. Contents 1 Introduction 2 2 On the Hardness of Unlabeled Multi-Robot Motion Planning 19 3 Efficient Multi-Robot Motion Planning for Unlabeled Discs in Simple Polygons 31 4 Motion Planning for Unlabeled Discs with Optimality Guarantees 41 5 Finding a Needle in an Exponential Haystack: Discrete RRT for Exploration of Implicit Roadmaps in Multi-Robot Motion Planning 53 6 New Perspective on Sampling-based Motion Planning via Random Geometric Graphs 67 7 Sampling-Based Bottleneck Pathfinding with Applications to Fr´echet Matching 87 8 Efficient Sampling-based Bottleneck Pathfinding over Cost Maps 105 9 The Critical Radius in Sampling-based Motion Planning 113 10 Conclusion and Future Work 125 11 Bibliography 129 1 Introduction Remark: This notation, which appears throughout the introduction, indicates that the corresponding text describes a contribution of the author that is part of this thesis. Motion planning is a fundamental problem in robotics concerned with allowing autonomous robots to efficiently navigate in environments cluttered with obstacles. Although motion planning was initially studied as a theoretical problem in computer science [29], nowadays it is applied in various fields. Notably, it arises in coordination of multiple autonomous vehicles [23], steering surgical needles [9], and planning trajectories of spacecrafts in orbit [94], to name just a few examples. Unfortunately, motion planning is notoriously challenging|both theoretically and practically|and many aspects of the problem are not sufficiently understood, even after 30 years of extensive multidisciplinary research. The complexity of the problem can be attributed to its continuous and high-dimensional search space, which accounts for (i) the geometric structure of the robot, which may consist of several rigid bodies connected through joints, (ii) the physical constraints that it needs to satisfy, e.g., velocity constraints and limited steering angle as a car has, (iii) and the environment in which it operates, which may change with time, contain unexpected obstacles (as pedestrians jumping into the road), or be a priori unknown altogether. In its most basic form, motion planning consists of finding collision-free paths for a robot in a (two or three-dimensional) workspace cluttered with static obstacles. The spatial pose of the robot, or its configuration, is uniquely defined by its degrees of freedom (DoFs). The set of all configurations is C termed the configuration space of the robot, and decomposes into the disjoint sets of free and forbidden configurations, namely and , respectively. Thus, given start and target configurations, the F ⊆ C C n F T T P1 P1 S P2 S P2 (a) (b) Figure 1.1: Motion planning for a square robot translating in the plane. In (a) the start and target configu- rations S; T , are denoted by the blue and pink squares, respectively. The robot is confined to a room (black border) which contains two triangular obstacles (gray). In (b), the forbidden regions of the configurations space are drawn in gray, whereas the white region is the free space. Observe that the depicted path is entirely collision free. problem can be restated as the task of finding a continuous curve in connecting the two configurations. F See a simple example in Figure 1.1. It is important to note that the input to the problem consists of only a representation of the robot R and the workspace in which it operates, whereas the structure of the free space is implicitly induced F by those parameters.
Recommended publications
  • Acknowledgements
    Acknowledgements So many people have made a significant contribution to this thesis in various ways. Al- though all of them provided me with valuable information, a few played a more direct role in the preparation of this thesis. First of all, I extend my gratitude to my promotor, Mark Overmars, and my co-promotor, Otfried Cheong for their perfect supervision. During the writing of my Ph.D. thesis, Mark Overmars provided many corrections and suggestions for improvement of the manuscript, for which I’m grateful. I am deeply indebted to Otfried Cheong: When I was a M.Sc. student at POSTECH in Korea, he motivated me to do a Ph.D. in Computational Geometry and provided me an offer of being his first Ph.D. student. With unfailing courtesy and monumental patience, he have supervised me in a perfect way, in Hong Kong and the Netherlands. I would also like to thank Siu-Wing Cheng and Mordecai Golin. Siu-Wing Cheng had advised me in various ways, and we had worked together on several problems. Mordecai Golin had showed me interesting geometry problems that I challenged to solve. I should also thank Rene´ van Oostrum. When we were in Hong Kong, I learned from him how to develope films and print photographs. He also helped me a lot when I settled down to the life in the Netherlands, and translated “Summary” into Dutch for this thesis. I must acknowledge my debt to the co-authors of the papers of which this thesis is com- posed: apart from Otfried Cheong, Siu-Wing Cheng and Rene´ van Oostrum, these are Mark de Berg, Prosenjit Bose, Dan Halperin, Jirˇ´ı Matousek,ˇ and Jack Snoeyink.
    [Show full text]
  • 3SUM with Preprocessing
    Data Structures Meet Cryptography: 3SUM with Preprocessing Alexander Golovnev Siyao Guo Thibaut Horel Harvard NYU Shanghai MIT [email protected] [email protected] [email protected] Sunoo Park Vinod Vaikuntanathan MIT & Harvard MIT [email protected] [email protected] Abstract This paper shows several connections between data structure problems and cryptography against preprocessing attacks. Our results span data structure upper bounds, cryptographic applications, and data structure lower bounds, as summarized next. First, we apply Fiat{Naor inversion, a technique with cryptographic origins, to obtain a data-structure upper bound. In particular, our technique yields a suite of algorithms with space S and (online) time T for a preprocessing version of the N-input 3SUM problem where S3 · T = Oe(N 6). This disproves a strong conjecture (Goldstein et al., WADS 2017) that there is no data structure that solves this problem for S = N 2−δ and T = N 1−δ for any constant δ > 0. Secondly, we show equivalence between lower bounds for a broad class of (static) data struc- ture problems and one-way functions in the random oracle model that resist a very strong form of preprocessing attack. Concretely, given a random function F :[N] ! [N] (accessed as an oracle) we show how to compile it into a function GF :[N 2] ! [N 2] which resists S-bit prepro- cessing attacks that run in query time T where ST = O(N 2−") (assuming a corresponding data structure lower bound on 3SUM). In contrast, a classical result of Hellman tells us that F itself can be more easily inverted, say with N 2=3-bit preprocessing in N 2=3 time.
    [Show full text]
  • Jean-Paul Laumond
    San Francisco CA 1:51:39 m4v Jean-Paul Laumond An interview conducted by Selma Šabanović with Matthew R. Francisco September 27 2011 Q: So if we can start with your name, and where you were born and when? Jean-Paul Laumond: Okay I'm Jean-Paul Laumond. I born in '53 in countryside North from Toulouse in France, in a small village in France. Q: And where did you go to school? Jean-Paul Laumond: I have been to school in Brive which is the main city of the area in that countryside, and after that I entered the university in Toulouse, first by following special training in French which is what we call the “classe préparatoire” for the engineering school. But in fact after two years I moved to university to in the mathematics department and I got a diploma to be a teacher in mathematics. Q: What did you study while you were in university and how did you decide on that particular direction? Jean-Paul Laumond: <clears throat> At the very beginning, I was not very convinced by the choice I made to enter into engineering, because engineering is to go towards the industry world while I was more interested by the academic position. And at that time I didn't know that engineering could be a possibility to enter the university or to make then. Then for me it was just pure abstraction or like literature, and then this is why and of course I was very enthusiastic with mathematics, and this is why I chosen to enter in the university in the department of mathematics.
    [Show full text]
  • Creative and Coordinated Computation
    Creative and Coordinated Computation Inaugural address delivered by Marc van Kreveld Professor in Computational Geometry and its Application Department of Information and Computing Sciences Faculty of Science Utrecht University on Friday, January 17, 2014 Utrecht, The Netherlands c Marc van Kreveld, 2014 Rector magnificus, colleagues, family, friends, ... I am honored to stand before you today, and have the opportunity to tell you all about my work, my research, and some other things that I will get to later. It is Friday afternoon, after 4 o'clock, and I realize that most people would call this the beginning of the weekend. However, I am going to be talking about scientific work for a while, so bear with me. I promise that I will not show any formulas, but I will show many illustrations. I truly hope that everyone in the audience will hear something worthwhile in this lecture. My research is related to geometry, a branch of mathematics that deals with objects, like points, lines, triangles and circles, and addresses rela- tions between these objects, like distances, intersections, and containment, or properties like lengths, areas, and angles. My research is also about al- gorithms, the use of automated methods to execute tasks, and the formal study of these methods. The third aspect of my research is applications, because points, triangles and circles can have a concrete meaning in appli- cations only, and the application dictates which tasks we want to perform on the geometry. The title of this speech, \Creative and Coordinated Computation", may seem contradictory: a creative process is often not coordinated, and more- over, coordination may obstruct creativity.
    [Show full text]
  • Geometric Problems in Cartographic Networks
    Geometric Problems in Cartographic Networks Geometrische Problemen in Kartografische Netwerken (met een samenvatting in het Nederlands) PROEFSCHRIFT ter verkrijging van de graad van doctor aan de Universiteit Utrecht op gezag van de Rector Magnificus, Prof. Dr. W.H. Gispen, ingevolge het besluit van het College voor Promoties in het openbaar te verdedigen op maandag 29 maart 2004 des middags te 16:15 uur door Sergio Cabello Justo geboren op 1 december 1977, te Lleida Promotor: Prof. Dr. Mark H. Overmars Copromotor: Dr. Marc J. van Kreveld Faculteit Wiskunde en Informatica Universiteit Utrecht Advanced School for Computing and Imaging This work was carried out in the ASCI graduate school. ASCI dissertation series number 99. This work has been supported mainly by the Cornelis Lely Stichting, and par- tially by a Marie Curie Fellowship of the European Community programme \Combinatorics, Geometry, and Computation" under contract number HPMT- CT-2001-00282, and a NWO travel grant. Dankwoord / Agradecimientos It is my wish to start giving my deepest thanks to my supervisor Marc van Kreveld and my promotor Mark Overmars. I am also very grateful to Mark de Berg, who also participated in my supervision in the beginning. Without trying it, you made me think that I was in the best place to do my thesis. I would also like to thank Pankaj Agarwal, Mark de Berg, Jan van Leeuwen, Gun¨ ter Rote, and Dorothea Wagner for taking part in the reading committee and giving comments. I would also like to thank the co-authors who directly par- ticipate in this thesis: Mark de Berg, Erik Demaine, Steven van Dijk, Yuanxin (Leo) Liu, Andrea Mantler, Gun¨ ter Rote, Jack Snoeyink, Tycho Strijk, and, of course, Marc van Kreveld.
    [Show full text]
  • Computational Geometry
    Computational Geometry Third Edition Mark de Berg · Otfried Cheong Marc van Kreveld · Mark Overmars Computational Geometry Algorithms and Applications Third Edition 123 Prof. Dr. Mark de Berg Dr. Marc van Kreveld Department of Mathematics Department of Information and Computer Science and Computing Sciences TU Eindhoven Utrecht University P.O. Box 513 P.O. Box 80.089 5600 MB Eindhoven 3508 TB Utrecht The Netherlands The Netherlands [email protected] [email protected] Dr. Otfried Cheong, ne´ Schwarzkopf Prof. Dr. Mark Overmars Department of Computer Science Department of Information KAIST and Computing Sciences Gwahangno 335, Yuseong-gu Utrecht University Daejeon 305-701 P.O. Box 80.089 Korea 3508 TB Utrecht [email protected] The Netherlands [email protected] ISBN 978-3-540-77973-5 e-ISBN 978-3-540-77974-2 DOI 10.1007/978-3-540-77974-2 ACM Computing Classification (1998): F.2.2, I.3.5 Library of Congress Control Number: 2008921564 © 2008, 2000, 1997 Springer-Verlag Berlin Heidelberg This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilm or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer. Violations are liable for prosecution under the German Copyright Law. The use of general descriptive names, registered names, trademarks, etc.
    [Show full text]
  • Algorithms for Robotic Motion and Manipulation Taylor &Francis Taylor & Francis Group Algorithms for Robotic Motion and Manipulation
    Algorithms for Robotic Motion and Manipulation Taylor &Francis Taylor & Francis Group http://taylorandfrancis.com Algorithms for Robotic Motion and Manipulation 1996 Workshop on the Algorithmic Foundations of Robotics edited, by Jean-Paul Laumond LAAS-CNRS Toulouse, France Mark Overmars Utrecht University Utrecht, The Netherlands Boca Raton London New York CRC Press is an imprint of the Taylor & Francis Group, an informa business First published 1997 by AK Peters Ltd. Published 2018 by CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boca Raton, FL 33487-2742 © 1997 by Taylor & Francis Group, LLC CRC Press is an imprint ofTaylor & Francis Group, an Informa business No claim to original U.S. Government works ISBN-13: 978-1-56881-067-6 (hbk) This book contains information obtained from authentic and highly regarded sources. Reasonable efforts have been made to publish reliable data and information, but the author and publisher cannot assume responsibility for the validity of all materials or the consequences of their use. The authors and publishers have attempted to trace the copyright holders of all material reproduced in this publication and apologize to copyright holders if permission to publish in this form has not been obtained. If any copyright material has not been acknowledged please write and let us know so we may rectify in any future reprint. Except as permitted under U.S. Copyright Law, no part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers.
    [Show full text]
  • Computational Geometry Lectures
    Computational Geometry Lectures Olivier Devillers & Monique Teillaud Bibliography Books [30, 19, 18, 45, 66, 70] 1 Convex hull: definitions, classical algorithms. • Definition, extremal point. [66] • Jarvis algorithm. [54] • Orientation predicate. [55] • Buggy degenerate example. [36] • Real RAM model and general position hypothesis. [66] • Graham algorithm. [50] • Lower bound. [66] • Other results. [67, 68, 58, 56, 8, 65, 7] • Higher dimensions. [82, 25] 2 Delaunay triangulation: definitions, motivations, proper- ties, classical algorithms. • Space of spheres [31, 32] • Delaunay predicates. [42] • Flipping trianagulation [52] • Incremental algorithm [57] • Sweep-line [48] • Divide&conquer [74] • Deletion [35, 20, 37] 1 3 Probabilistic analyses: randomized algorithms, evenly dis- tributed points. • Randomization [29, 73, 14] – Delaunay tree [16, 17] and variant [51] – Jump and walk [63, 62] – Delaunay hierarchy [34] – Biased random insertion order [6] – Accelerated algorithms [28, 72, 33, 26] • Poisson point processes [71, 64] – Straight walk [44, 27] – Visibility walk [39] – Walks on vertices [27, 41, 59] – Smoothed analysis [75, 38] 4 Robustness issues: numerical issues, degenerate cases. • IEEE754 [49] • Orientation with double [55] • Solution 1: no geometric theorems [76] • Exact geometric computation paradigm [81] • Perturbations – controlled [61] – symbolic: SoS [46], world [2], 4th dim [43], “qualitative” [40] 5 Triangulations in the CGAL library. • https://doc.cgal.org/latest/Manual/packages.html#PartTriangulationsAndDelaunayTriangulations
    [Show full text]
  • Path Planning in Dynamic Environments
    Path Planning in Dynamic Environments Typesetting: This thesis was typeset by the author using LATEX2 Cover design: The cover was designed by Lucius, Groningen, using Adobe Illustrator CS2 Cover illustration: Lucius, Compositie 29 in groen en geel: ‘Lentewandeling’ (detail) Printed in The Netherlands by Drukkerij Bariet, Ruinen ISBN: 978-90-393-4480-4 Copyright © 2007 by Jur van den Berg. All rights reserved. Path Planning in Dynamic Environments Padplanning in dynamische omgevingen (met een samenvatting in het Nederlands) Proefschrift ter verkrijging van de graad van doctor aan de Universiteit Utrechtopgezagvanderectormagnificus,prof.dr.W.H. Gispen, ingevolge het besluit van het college voor promoties in het openbaar te verdedigen op woensdag 4 april 2007 des middags te 2.30 uur door JurPietervandenBerg geboren op 27 mei 1981 te Groningen Promotor: Prof. dr. M.H. Overmars This work was financially supported by the IST Programme of the EU as a Shared-cost RTD (FET Open) Project under Contract No IST-2001-39250 (MOVIE - Motion Planning in Virtual Environments). The Road Not Taken Two roads diverged in a yellow wood, And sorry I could not travel both And be one traveler, long I stood And looked down one as far as I could To where it bent in the undergrowth; Then took the other, as just as fair, And having perhaps the better claim, Because it was grassy and wanted wear; Though as for that the passing there Had worn them really about the same, And both that morning equally lay In leaves no step had trodden black. Oh, I kept the first for another day! Yet knowing how way leads on to way, I doubted if I should ever come back.
    [Show full text]
  • Computational Geometry Through the Information Lens Mihai Pdtracu
    Computational Geometry through the Information Lens by Mihai Pdtracu Submitted to the Department of Electrical Engineering and Computer Science in partial fulfillment of the requirements for the degree of Master of Science at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY June 2007 © Massachusetts Institute of Technology 2007. All rights reserved. A uthor ........................................... L............... ........ Department of Electrical Engineering and Computer Science May 22, 2007 Certified by .......................... Erik D. Demaine Associate Professor Thesis Supervisor Accepted by.... .. .. .......... .. .......... ... ..-- - ............... Arthur C. Smith Chairman, Department Committee on Graduate Students BARKEfR MASSACHUSETTS INMTITUTE OF TECHNOLOGY AUG 16 2007 URRIEFS cl Computational Geometry through the Information Lens by Mihai Pdtra§cu Submitted to the Department of Electrical Engineering and Computer Science on May 22, 2007, in partial fulfillment of the requirements for the degree of Master of Science Abstract This thesis revisits classic problems in computational geometry from the modern algorithmic perspective of exploiting the bounded precision of the input. In one dimension, this viewpoint has taken over as the standard model of computation, and has led to a powerful suite of techniques that constitute a mature field of research. In two or more dimensions, we have seen great success in understanding orthogonal problems, which decompose naturally into one dimensional problems. However, problems of a nonorthogonal nature, the core of computational geometry, have remained uncracked for many years despite extensive effort. For example, Willard asked in SODA'92 for a o(n lg n) algorithm for Voronoi diagrams. Despite growing interest in the problem, it was not successfully solved until this thesis. Formally, let w be the number of bits in a computer word, and consider n points with O(w)-bit rational coordinates.
    [Show full text]
  • Sample Contributed Book
    Sample Contributed Bo ok cbook 26/2/1998 22:49—PAGE PROOFS for John Wiley & Sons Ltd (jwcbook.sty v5.0, 17-4-1997) ii cbook 26/2/1998 22:49—PAGE PROOFS for John Wiley & Sons Ltd (jwcbook.sty v5.0, 17-4-1997) Sample Contributed Bo ok Edited by J. SMITH JOHN WILEY & SONS . Chichester New York Brisbane Toronto Singap ore cbook 26/2/1998 22:49—PAGE PROOFS for John Wiley & Sons Ltd (jwcbook.sty v5.0, 17-4-1997) iv cbook 26/2/1998 22:49—PAGE PROOFS for John Wiley & Sons Ltd (jwcbook.sty v5.0, 17-4-1997) Contents cbook 26/2/1998 22:49—PAGE PROOFS for John Wiley & Sons Ltd (jwcbook.sty v5.0, 17-4-1997) vi CONTENTS cbook 26/2/1998 22:49—PAGE PROOFS for John Wiley & Sons Ltd (jwcbook.sty v5.0, 17-4-1997) 4 Probabilistic Roadmaps for Rob ot Path Planning Lydia E. Kavraki Jean-Claude Latombe Department of Computer Scince, Rice University, Houston, TX 77005 Department of Computer Science, Stanford University, Stanford, CA 94305 Abstract The ProbabilisticRoadMap planner (PRM) has been applied with success to multiple planning problems involving robots with 3 to 16 degrees of freedom (dof) operating in known static environments. This paper describes the planner and reports on experimental and theoretical results related to its performance. PRM computation consists of a preprocessing and a query phase. Preprocessing, which is done only once for a given environment, generates a roadmap of randomly, but properly selected, collision-free configurations (nodes). Planning then connects any given initial and final configurations of the robot to two nodes of the roadmap and computes a path through the roadmap between these two nodes.
    [Show full text]
  • Bibliography
    Bibliography [Ach95] Alf-Christian Achilles. The collection of computer science bibli- ographies. http://liinwww.ira.uka.de/bibliography/, 1995. [AF84] John Ahn and Herbert Freeman. A program for automatic name placement. Cartographica, 21(2{3):101{109, 1984. [AH95] David H. Alexander and Carl S. Hantman. Automating linear text placement within dense feature networks. In Proc. Auto- Carto 12, pages 311{320. ACSM/ASPRS, Bethesda, 1995. [AIK89] Hiromi Aonuma, Hiroshi Imai, and Yahiko Kambayashi. A visual system of placing characters appropriately in multimedia map databases. In Proceedings of the IFIP TC 2/WG 2.6 Working Conference on Visual Database Systems, pages 525{546. North- Holland, 1989. [Ali62] Georges Alinhac. Cartographie Th´eorique et Technique, chap- ter IV. Institut G´eographique National, Paris, 1962. [AvKS98] Pankaj K. Agarwal, Marc van Kreveld, and Subhash Suri. Label placement by maximum independent set in rectangles. Compu- tational Geometry: Theory and Applications, 11:209{218, 1998. [Bar97] Mathieu Barrault. An automated system for name placement which complies with cartographic quality criteria: The hydro- graphic network. In Proceedings of the Conference on Spatial Information Theory (COSIT'97), volume 1329 of Lecture Notes in Computer Science, pages 499{500, Pittsburgh, PA, 1997. Springer-Verlag. [Bes94] Christian Bessi`ere. Arc-consistency and arc-consistency again. Artificial Intelligence, 65:179{190, 1994. [BFR95] Christian Bessi`ere, Eugene C. Freuder, and Jean-Charles R´egin. Using inference to reduce arc-consistency computation. In Proc. International Joint Conference on Artificial Intelligence, Montr´eal, August 1995. 140 Bibliography [BL95] Mathieu Barrault and Fran¸cois Lecordix. An automated system for linear feature name placement which complies with carto- graphic quality criteria.
    [Show full text]