Efficient Mission Planning for Robot Networks in Communication Constrained Environments Md Mahbubur Rahman [email protected]
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Florida International University FIU Digital Commons FIU Electronic Theses and Dissertations University Graduate School 6-6-2017 Efficient Mission Planning for Robot Networks in Communication Constrained Environments md mahbubur rahman [email protected] DOI: 10.25148/etd.FIDC001910 Follow this and additional works at: https://digitalcommons.fiu.edu/etd Part of the Artificial Intelligence and Robotics Commons Recommended Citation rahman, md mahbubur, "Efficient Mission Planning for Robot Networks in Communication Constrained Environments" (2017). FIU Electronic Theses and Dissertations. 3484. https://digitalcommons.fiu.edu/etd/3484 This work is brought to you for free and open access by the University Graduate School at FIU Digital Commons. It has been accepted for inclusion in FIU Electronic Theses and Dissertations by an authorized administrator of FIU Digital Commons. For more information, please contact [email protected]. FLORIDA INTERNATIONAL UNIVERSITY Miami, Florida EFFICIENT MISSION PLANNING FOR ROBOT NETWORKS IN COMMUNICATION CONSTRAINED ENVIRONMENTS A dissertation submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY in COMPUTER SCIENCE by Md Mahbubur Rahman 2017 To: Interim Dean Ranu Jung College of Engineering and Computing This dissertation, written by Md Mahbubur Rahman, and entitled Efficient Mission Planning for Robot Networks in Communication Constrained Environments, having been approved in respect to style and intellectual content, is referred to you for judgment. We have read this dissertation and recommend that it be approved. Bogdan Carbunar Ning Xie Wei Zeng Ali Mostafavi Leonardo Bobadilla, Major Professor Date of Defense: June 06, 2017 The dissertation of Md Mahbubur Rahman is approved. Interim Dean Ranu Jung College of Engineering and Computing Andr´es G. Gil Vice President for Research and Economic Development and Dean of the University Graduate School Florida International University, 2017 ii c Copyright 2017 by Md Mahbubur Rahman All rights reserved. iii DEDICATION To my family for their unconditional love and support. iv ACKNOWLEDGMENTS The research works presented in this dissertation came into a success because of many people who helped me in many ways. First of all, I would like to thank my adviser Dr Leonardo Bobadilla who paved the way for completing the research in time through his continuous support and great advice. He made robotics very interesting to me and we had many fruitful hours of discussions on research topics while eating in restaurants, attending conferences, walking around and riding in car. My gratitude goes to other committee members, Dr Bogdan, Dr Ali, Dr Ning and Dr Zeng for their time and valuable feedback. I would like to thank my sibling research mates, Sebastian, Tauhid, and Greg. I not only shared a lab with these amazing guys but also discussed many research ideas and they provided me lots of constructive feedback about my presentations. Three other guys Triana, Franklin and Carlos helped me with the experiments and simulation works and I am really proud to be a mentor of these bright students. I am grateful to Florida International University’s Graduate School for support- ing me with the Dissertation Year Fellowship award. My special gratitude goes to US Army Research Lab for funding a number of my research projects. v ABSTRACT OF THE DISSERTATION EFFICIENT MISSION PLANNING FOR ROBOT NETWORKS IN COMMUNICATION CONSTRAINED ENVIRONMENTS by Md Mahbubur Rahman Florida International University, 2017 Miami, Florida Professor Leonardo Bobadilla, Major Professor Many robotic systems are remotely operated nowadays that require uninterrupted connection and safe mission planning. Such systems are commonly found in military drones, search and rescue operations, mining robotics, agriculture, and environmen- tal monitoring. Different robotic systems may employ disparate communication modalities such as radio network, visible light communication, satellite, infrared, Wi-Fi. However, in an autonomous mission where the robots are expected to be in- terconnected, communication constrained environment frequently arises due to the out of range problem or unavailability of signal. Furthermore, several automated projects (building construction, assembly line) do not guarantee uninterrupted com- munication, and a safe project plan is required that optimizes collision risks, cost and duration. In this thesis, we propose four pronged approaches to alleviate some of these issues: 1) Communication aware world mapping; 2) Communication pre- serving using the Line-of-Sight (LoS); 3) Communication aware safe planning; and 4) Multi-Objective motion planning for navigation. First, we focus on developing a communication aware world map that integrates traditional world models with the planning of multi-robot placement. Our proposed communication map selects the optimal placement of a chain of intermediate relay vehicles in order to maximize communication quality to a remote unit. We also vi propose an algorithm to build a min-Arborescence tree when there are multiple remote units to be served. Second, in communication denied environments, we use Line-of-Sight (LoS) to establish communication between mobile robots, control their movements and relay information to other autonomous units. We formulate and study the complexity of a multi-robot relay network positioning problem and propose approximation al- gorithms that restore visibility based connectivity through the relocation of one or more robots. Third, we develop a framework to quantify the safety score of a fully automated robotic mission where the coexistence of human and robot may pose a collision risk. A number of alternate mission plans are analyzed using motion planning algorithms to select the safest one. Finally, an efficient multi-objective optimization based path planning for the robots is developed to deal with several Pareto optimal cost attributes. vii TABLE OF CONTENTS CHAPTER PAGE 1. INTRODUCTION ............................... 1 1.1 Motivation................................... 1 1.2 Fundamental Challenges and Key Themes . 5 1.3 RelatedWork................................. 8 1.4 Thesis Organization and Contribution . 12 2. COMMUNICATION AWARE MAPPING . 16 2.1 RelayBasedCommunication. 16 2.2 RelatedWork................................. 17 2.3 MathematicalFormulation. 19 2.3.1 Communication Quality . 20 2.3.2 RelayPlacementProblems. 21 2.4 Single Unit Multiple Relay Placement . 23 2.5 Multiple Unit Multiple Relay Placement . 28 2.6 ExperimentalResults............................. 31 2.6.1 SoftwareSimulation ............................ 32 2.6.2 HardwareExperiment ........................... 34 2.6.3 NumericalAnalysis............................. 36 2.7 DiscussionandExtension .......................... 38 3. COMMUNICATION BASED ON LINE-OF-SIGHT . 40 3.1 Visibility Based Communication . 40 3.2 RelatedWork................................. 42 3.3 Preliminaries ................................. 44 3.4 ProblemStatement.............................. 44 3.4.1 Communication State Validity . 44 3.4.2 Invalid-to-Valid Communication State Restoration . 46 3.4.3 Patrolling and Trajectory Estimation . 46 3.5 Communication State Validation . 47 3.5.1 Centralized Algorithm . 47 3.5.2 Distributed Algorithm . 50 3.6 Recovering a Communication-valid State with a Single Vehicle . 51 3.7 Recovering a Communication-valid State with Multiple Vehicles . 54 3.7.1 Hardness of Relocating Multiple Robots . 54 3.7.2 ApproximatedSolution. .. .. 55 3.7.3 Multi-Robot Placements and Patrolling . 58 3.8 ExperimentalResults............................. 61 3.8.1 Checking Communication-Valid State . 61 3.8.2 Regaining a Communication-valid State by Single Vehicle Movement . 62 3.8.3 Re-Establishing a Communication-valid State . 66 viii 3.8.4 PhysicalDeployment............................ 70 3.9 Summary ................................... 72 4. COMMUNICATION AWARE SAFE PLANNING . 74 4.1 Approach ................................... 75 4.2 RelatedWork................................. 76 4.3 ProblemFormulation............................. 78 4.3.1 ActivityGraph ............................... 78 4.3.2 ConstructionPhysicalStateSpace . 78 4.3.3 Augmented Discrete Event System Specification . .. 79 4.3.4 Safety Evaluation for Different Plans . 81 4.4 SystemOverview ............................... 82 4.5 Plan Extraction from an Activity Graph . 84 4.6 Event Scheduling Using Augmented DEVS . 86 4.7 MotionPlanner................................ 88 4.7.1 Planning under Differential Constraints . 88 4.7.2 PlanningfortheWorkers . .. .. 89 4.7.3 Safest path avoiding moving bodies . 91 4.8 Coordination Space to Prevent Robot-Robot Collision . .. 93 4.9 SafetyModel ................................. 94 4.10 OptimalPlanComputation . 95 4.11CaseStudyExamples............................. 97 4.11.1 Alternative Plans and Activity Scheduling . 97 4.11.2 Discrete Event Scheduling . 98 4.11.3 Motion Planning and Coordination . 99 4.11.4 SafetyEvaluation. .. .. .. .104 4.11.5 Sensitivity Analysis . 105 4.11.6 Managerial Implications and Discussions . 107 4.12 DiscussionsandFutureWork . .108 5. COMMUNICATION PRESERVING MULTI-OPTIMAL MOTION PLAN- NING ......................................110 5.1 Visibility as an Objective Function and Motivation . 110 5.2 RelatedWork .................................112 5.3 Preliminaries .................................114 5.4 Traditional RRT* and Multiobjective Costs . 116 5.5 ChoosingaParent ..............................117 5.6