Delft University of Technology Agent-based architectures supporting fault-tolerance in small satellites Carvajal Godínez, J. DOI 10.4233/uuid:b528d7be-e82d-4205-abdf-3fb3fa7f1011 Publication date 2021 Document Version Final published version Citation (APA) Carvajal Godínez, J. (2021). Agent-based architectures supporting fault-tolerance in small satellites. https://doi.org/10.4233/uuid:b528d7be-e82d-4205-abdf-3fb3fa7f1011 Important note To cite this publication, please use the final published version (if applicable). Please check the document version above. Copyright Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons. Takedown policy Please contact us and provide details if you believe this document breaches copyrights. We will remove access to the work immediately and investigate your claim. This work is downloaded from Delft University of Technology. For technical reasons the number of authors shown on this cover page is limited to a maximum of 10. AGENT-BASED ARCHITECTURES SUPPORTING FAULT-TOLERANCEIN SMALL SATELLITES AGENT-BASED ARCHITECTURES SUPPORTING FAULT-TOLERANCEIN SMALL SATELLITES Dissertation for the purpose of obtaining the degree of doctor at Delft University of Technology by the authority of the Rector Magnificus, Prof. dr. ir. T.H.J.J. van der Hagen, chair of the Board for Doctorates, to be defended publicly on Monday 8 February 2021 at 10:00 o’clock by Johan CARVAJAL-GODÍNEZ Master of Engineering in Modern Manufacturing Systems, Instituto Tecnológico de Costa Rica, Cartago, Costa Rica, born in San Jose, Costa Rica. This dissertation has been approved by the promotors. Composition of the doctoral committee: Rector Magnificus, chairperson Prof. dr. E.K.A. Gill Delft University of Technology, promotor Dr. J. Guo Delft University of Technology, copromotor Independent members: Prof. dr. A. van Deursen Delft University of Technology Prof. dr. ir. M. Mulder Delft University of Technology Prof. dr. S. Montenegro Wurzburg University Prof. dr. E. Caldwell University of Costa Rica Dr. Ir. M. Verhoef European Space Agency This research was funded by Costa Rica Institute of Technology, and also supported by the Delft University of Technology. Prof. dr. E.K.A. Gill and Dr. Jian Guo contributed significantly to the realization of the thesis. Keywords: Small Satellites, Onboard Software, Multi-Agent Systems, Satellite Soft- ware Architecture, Onboard Satellite Communication, Fault Tolerance Printed by: IPSKAMP printing Front & Back: Becki Corrales Brenes Copyright © 2021 by J. Carvajal-Godínez ISBN 000-00-0000-000-0 An electronic version of this dissertation is available at http://repository.tudelft.nl/. We can only see a short distance ahead, but we can see plenty there that needs to be done. Alan Turing Dedicated to my father Alexis Carvajal-Arias (1946-2019) CONTENTS Summary xi Samenvatting xiii Acronyms xvii List of Symbols xxi 1 Introduction 1 1.1 The Evolution of Spacecraft Computers...................2 1.2 Trends in Miniaturized Satellites Engineering................3 1.2.1 Subsystem Miniaturization.....................5 1.2.2 Software-defined Components....................6 1.2.3 Emerging Onboard Computing Technologies............6 1.2.4 Integrated Fault Detection, Isolation and Recovery.........8 1.2.5 The need for a more reliable and precise AOCS...........8 1.3 The Software Complexity Problem.....................9 1.4 Software Architecture Paradigms...................... 10 1.5 An Overview on Multi-Agent Systems.................... 11 1.5.1 Agents vs Multi-Agent Systems.................... 11 1.5.2 Agent Communication Architectures................ 12 1.5.3 Multi-Agents Systems Frameworks.................. 13 1.5.4 MAS-based Applications in Control Systems............. 14 1.5.5 MAS-based Software in Space Applications............. 14 1.6 Enabling Technologies for MAS-based Software............... 15 1.6.1 Multi-Agent Systems Infrastructure................. 15 1.6.2 MAS-based Software Design Considerations............. 16 1.7 Motivation and Contributions....................... 17 1.7.1 Research Motivation and Requirements............... 18 1.7.2 Research Questions......................... 19 1.7.3 Research Methodology........................ 21 1.8 Dissertation Structure............................ 22 2 Essentials of Attitude and Orbit Determination 25 2.1 Systems Architecture Approach....................... 26 2.2 AOCS Modeling Concepts.......................... 27 2.2.1 Reference Frames.......................... 27 2.2.2 Satellite Orbit Model in LEO..................... 28 2.2.3 Attitude Representation....................... 28 2.2.4 Attitude Modeling.......................... 30 vii viii CONTENTS 2.2.5 Attitude perturbation Modeling................... 32 2.2.6 Sensor Measurement Model..................... 33 2.3 Onboard Attitude Determination...................... 34 2.3.1 Challenges on Multi-Sensor Data Fusion.............. 35 2.3.2 Data Fusion Techniques....................... 35 2.3.3 Reference Algorithm for Attitude Estimation............. 36 3 Agent-based Fault Detection and Recovery 39 3.1 FDIR Methods for Control Systems..................... 41 3.2 Agent-based Architecture for FDIR..................... 43 3.2.1 FDIR Implementation Options.................... 43 3.2.2 Trade-off Criteria........................... 44 3.2.3 Trade-off Analysis.......................... 45 3.3 AOCS Case Study.............................. 47 3.3.1 System Model............................ 47 3.3.2 Gyroscope Measurement Model................... 49 3.3.3 Gyroscope Fault Modeling...................... 49 3.3.4 Gyroscope Installation........................ 50 3.3.5 Fault Detection and Identification Algorithm............ 51 3.3.6 Fault Recovery Algorithm...................... 52 3.3.7 Agent-based FDIR Implementation................. 53 3.3.8 Simulation Scenarios........................ 54 3.4 Results Analysis............................... 60 3.5 Chapter Summary............................. 61 4 Multi-Agent Communication in Satellite Software 63 4.1 Agent Communication Languages..................... 65 4.1.1 Agent Interaction Protocols..................... 66 4.1.2 Message Transport Protocol Implementation............ 67 4.2 Software Communication Architecture................... 69 4.3 AOCS Case Study.............................. 71 4.3.1 AOCS Reference Architecture.................... 71 4.3.2 AOCS Measurement Model..................... 72 4.3.3 Traffic Injection Model........................ 74 4.3.4 Communication Bus Load Modeling................. 74 4.4 Case Study Implementation......................... 75 4.4.1 CAN Channel Implementation.................... 75 4.4.2 Sensor Model Implementation.................... 78 4.5 Simulation Experiments.......................... 78 4.5.1 Satellite Operations Scenarios.................... 78 4.5.2 Simulation Configuration...................... 80 4.6 Simulation Results and Analysis....................... 82 4.6.1 Bus Utilization............................ 82 4.6.2 Measurement Delays......................... 85 4.6.3 Effect of Delays in Measurements Variance............. 88 4.6.4 Bus Utilization Balancing...................... 91 CONTENTS ix 4.7 Chapter Summary............................. 92 5 Model-Driven Methodology for Designing Agent-based Software 93 5.1 Modeling Software as a Multi-Agent System................. 95 5.1.1 Resource Mapping Strategy..................... 96 5.2 Multi-Agent Systems for Satellite Applications............... 97 5.3 ADCS Case Study.............................. 103 5.3.1 ADCS Physical Modeling....................... 104 5.3.2 MASSA: Analysis Phase........................ 105 5.3.3 MASSA: Design Phase........................ 107 5.3.4 MASSA: Verification Phase...................... 108 5.3.5 Results Analysis for the ADCS Case Study.............. 110 5.4 Proposed MASSA Validation Strategy.................... 112 5.5 Chapter Summary............................. 113 6 Organizational Optimization of Multi-Agent based Software 115 6.1 Organizational Structures for Agents.................... 117 6.2 Multi-Agents System Consensus...................... 118 6.2.1 Consensus Strategies and Algorithms................ 119 6.3 Topological Optimization of MAS-based Software............. 119 6.3.1 Topological Modeling of Multi Agent-based Software........ 119 6.3.2 Network Scale Effects........................ 122 6.3.3 Randomized Search Strategies.................... 123 6.4 Optimization Implementation....................... 125 6.5 Topological optimization for AOCS Software................ 126 6.5.1 PROBA 3 Mission Description.................... 126 6.5.2 Simulation Scenarios........................ 128 6.5.3 Simulation Approach........................ 132 6.5.4 Results and Analysis......................... 134 6.5.5 Validation of Results......................... 140 6.6 Conclusions and Remarks.......................... 140 7 Conclusions and Outlook 141 7.1 Research Synthesis and Conclusions.................... 142 7.2 Innovations and Contributions....................... 144 7.3 Research Outlook.............................. 145 7.3.1 New Applications.......................... 145 7.3.2 Implementation Aspects....................... 146 7.4 Recommendations............................. 146 References 149 A Appendix A - Orbital Elements 169 B Appendix B - Two Line Elements