Submodular optimization for risk-aware coordination of multi-robot systems

Placeholder Show Content

Abstract/Contents

Abstract
Robots are often designed for dangerous environments such as severe storms, but routing algorithms rarely are. This dissertation introduces a new class of routing problems with ``risky traversal'' where a robot may fail when travelling between two sites. Our key insight is that many objectives in the risky traversal model satisfy a diminishing returns property known as submodularity. We develop a set of tools based on submodular optimization which lead to efficient solutions for a wide variety of problems: 1. The "Team Surviving Orienteers" (TSO) problem, where the size of the team is fixed and we seek routes which maximize the expected rewards collected at nodes, subject to survival probability constraints on each robot. 2. The "On-line TSO" problem, where observations are incorporated to update the paths on-line in a parallel fashion (in response to survival events). 3. The "Heterogeneous TSO" problem, which allows robots to have different capabilities such as sensors (affecting rewards collected), actuation (affecting ability to traverse between sites), and robustness (affecting survival probabilities). 4. The "Matroid TSO" problem, where the set of routes must satisfy an `independence' constraint represented by a matroid, for example limits on the number of each type of robot available, traffic through regions of the environment, total risk budgets for the team, or combinations of these limits. 5. The "Risk Sensitive Coverage" problem, which is the dual to the TSO where the team must satisfy a coverage constraint (e.g., ensure that nodes are visited with specified probabilities) while using minimum resources (e.g., number of robots deployed, distance travelled, or expected number of failures). Our algorithms are based on the approximate greedy algorithm, where we iteratively select a path which approximately maximizes the expected incremental rewards subject to some constraints. Due to the submodular structure of the problems considered in this dissertation, we can prove bounds on the suboptimality of our algorithms. The approach developed in this dissertation provides a foundational set of tools for routing large scale teams in dangerous environments while explicitly planning for robot failure.

Description

Type of resource text
Form electronic resource; remote; computer; online resource
Extent 1 online resource.
Place California
Place [Stanford, California]
Publisher [Stanford University]
Copyright date 2018; ©2018
Publication date 2018; 2018
Issuance monographic
Language English

Creators/Contributors

Author Jorgensen, Stefan
Degree supervisor Pavone, Marco, 1980-
Thesis advisor Pavone, Marco, 1980-
Thesis advisor Schwager, Mac
Thesis advisor Van Roy, Benjamin
Thesis advisor Vondrak, Ján, (Mathematician)
Degree committee member Schwager, Mac
Degree committee member Van Roy, Benjamin
Degree committee member Vondrak, Ján, (Mathematician)
Associated with Stanford University, Department of Electrical Engineering.

Subjects

Genre Theses
Genre Text

Bibliographic information

Statement of responsibility Stefan Jorgensen.
Note Submitted to the Department of Electrical Engineering.
Thesis Thesis Ph.D. Stanford University 2018.
Location electronic resource

Access conditions

Copyright
© 2018 by Stefan Timothy Jorgensen
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

Also listed in

Loading usage metrics...