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Full-Text Articles in Operations Research, Systems Engineering and Industrial Engineering

Towards Reactive Control Of Transitional Legged Robot Maneuvers, Jeff Duperret Dec 2017

Towards Reactive Control Of Transitional Legged Robot Maneuvers, Jeff Duperret

Departmental Papers (ESE)

We propose the idea of a discrete navigation problem – consisting of controlling the state of a discrete-time control system to reach a goal set while in the interim avoiding a set of obstacle states – to approximate a simplified class of transitional legged robotic tasks such as leaping which have no well established mathematical description that lends itself to synthesis. The control relation given in Theorem 1 is (assuming a task solution exists) necessary and sufficient to solve a discrete navigation problem in a minimum number of steps, and is well suited to computation when a legged system’s continuous-time within-stride ...


Sensor-Based Legged Robot Homing Using Range-Only Target Localization, Vasileios Vasilopoulos, Omur Arslan, Avik De, Daniel E. Koditschek Dec 2017

Sensor-Based Legged Robot Homing Using Range-Only Target Localization, Vasileios Vasilopoulos, Omur Arslan, Avik De, Daniel E. Koditschek

Departmental Papers (ESE)

This paper demonstrates a fully sensor-based reactive homing behavior on a physical quadrupedal robot, using onboard sensors, in simple (convex obstacle-cluttered) unknown, GPS-denied environments. Its implementation is enabled by our empirical success in controlling the legged machine to approximate the (abstract) unicycle mechanics assumed by the navigation algorithm, and our proposed method of range-only target localization using particle filters.

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Modular Hopping And Running Via Parallel Composition, Avik De Nov 2017

Modular Hopping And Running Via Parallel Composition, Avik De

Departmental Papers (ESE)

Though multi-functional robot hardware has been created, the complexity in its functionality has been constrained by a lack of algorithms that appropriately manage flexible and autonomous reconfiguration of interconnections to physical and behavioral components.

Raibert pioneered a paradigm for the synthesis of planar hopping using a composition of ``parts'': controlled vertical hopping, controlled forward speed, and controlled body attitude. Such reduced degree-of-freedom compositions also seem to appear in running animals across several orders of magnitude of scale. Dynamical systems theory can offer a formal representation of such reductions in terms of ``anchored templates,'' respecting which Raibert's empirical synthesis (and ...


Ground Robotic Measurement Of Aeolian Processes, Feifei Qian, Douglas J. Jerolmack, Nicholas Lancaster, George Nikolich, Paul B. Reverdy, Sonia F. Roberts, Thomas F. Shipley, Robert Scott Van Pelt, Ted M. Zobeck, Daniel E. Koditschek Aug 2017

Ground Robotic Measurement Of Aeolian Processes, Feifei Qian, Douglas J. Jerolmack, Nicholas Lancaster, George Nikolich, Paul B. Reverdy, Sonia F. Roberts, Thomas F. Shipley, Robert Scott Van Pelt, Ted M. Zobeck, Daniel E. Koditschek

Departmental Papers (ESE)

Models of aeolian processes rely on accurate measurements of the rates of sediment transport by wind, and careful evaluation of the environmental controls of these processes. Existing field approaches typically require intensive, event-based experiments involving dense arrays of instruments. These devices are often cumbersome and logistically difficult to set up and maintain, especially near steep or vegetated dune surfaces. Significant advances in instrumentation are needed to provide the datasets that are required to validate and improve mechanistic models of aeolian sediment transport. Recent advances in robotics show great promise for assisting and amplifying scientists’ efforts to increase the spatial and ...


Joint Exploration Of Local Metrics And Geometry In Sampling-Based Planning, Vincent Pacelli Aug 2017

Joint Exploration Of Local Metrics And Geometry In Sampling-Based Planning, Vincent Pacelli

Departmental Papers (ESE)

This thesis addresses how the local geometry of the workspace around a system state can be combined with local metrics describing system dynamics to improve the connectivity of the graph produced by a sampling-based planner over a fixed number of configurations. This development is achieved through generalization of the concept of the local free space to inner products other than the Euclidean inner product. This new structure allows for naturally combining the local free space construction with a locally applicable metric. The combination of the local free space with two specific metrics is explored in this work. The first metric ...


Spatial Sampling Strategies With Multiple Scientific Frames Of Reference, Paul B. Reverdy, Thomas F. Shipley, Daniel E. Koditschek Jun 2017

Spatial Sampling Strategies With Multiple Scientific Frames Of Reference, Paul B. Reverdy, Thomas F. Shipley, Daniel E. Koditschek

Departmental Papers (ESE)

We study the spatial sampling strategies employed by field scientists studying aeolian processes, which are geophysical interactions between wind and terrain. As in geophysical field science in general, observations of aeolian processes are made and data gathered by carrying instruments to various locations and then deciding when and where to record a measurement. We focus on this decision-making process. Because sampling is physically laborious and time consuming, scientists often develop sampling plans in advance of deployment, i.e., employ an offline decision-making process. However, because of the unpredictable nature of field conditions, sampling strategies generally have to be updated online ...


Quasi-Static And Dynamic Mismatch For Door Opening And Stair Climbing With A Legged Robot, T. Turner Topping, Gavin Kenneally, Daniel E. Koditschek May 2017

Quasi-Static And Dynamic Mismatch For Door Opening And Stair Climbing With A Legged Robot, T. Turner Topping, Gavin Kenneally, Daniel E. Koditschek

Departmental Papers (ESE)

This paper contributes to quantifying the notion of robotic fitness by developing a set of necessary conditions that determine whether a small quadruped has the ability to open a class of doors or climb a class of stairs using only quasi-static maneuvers. After verifying that several such machines from the recent robotics literature are mismatched in this sense to the common human scale environment, we present empirical workarounds for the Minitaur quadrupedal platform that enable it to leap up, force the door handle and push through the door, as well as bound up the stairs, thereby accomplishing through dynamical maneuvers ...


Detecting Poisoning Attacks On Hierarchical Malware Classification Systems, Dan P. Guralnik, Bill Moran, Ali Pezeshki, Omur Arslan Mar 2017

Detecting Poisoning Attacks On Hierarchical Malware Classification Systems, Dan P. Guralnik, Bill Moran, Ali Pezeshki, Omur Arslan

Departmental Papers (ESE)

Anti-virus software based on unsupervised hierarchical clustering (HC) of malware samples has been shown to be vulnerable to poisoning attacks. In this kind of attack, a malicious player degrades anti-virus performance by submitting to the database samples specifically designed to collapse the classification hierarchy utilized by the anti-virus (and constructed through HC) or otherwise deform it in a way that would render it useless. Though each poisoning attack needs to be tailored to the particular HC scheme deployed, existing research seems to indicate that no particular HC method by itself is immune. We present results on applying a new notion ...


Sensory Steering For Sampling-Based Motion Planning, Omur Arslan, Vincent Pacelli, Daniel E. Koditschek Jan 2017

Sensory Steering For Sampling-Based Motion Planning, Omur Arslan, Vincent Pacelli, Daniel E. Koditschek

Departmental Papers (ESE)

Sampling-based algorithms offer computationally efficient, practical solutions to the path finding problem in high-dimensional complex configuration spaces by approximately capturing the connectivity of the underlying space through a (dense) collection of sample configurations joined by simple local planners. In this paper, we address a long-standing bottleneck associated with the difficulty of finding paths through narrow passages. Whereas most prior work considers the narrow passage problem as a sampling issue (and the literature abounds with heuristic sampling strategies) very little attention has been paid to the design of new effective local planners. Here, we propose a novel sensory steering algorithm for ...


Discriminative Measures For Comparison Of Phylogenetic Trees, Omur Arslan, Dan P. Guralnik, Daniel E. Koditschek Jan 2017

Discriminative Measures For Comparison Of Phylogenetic Trees, Omur Arslan, Dan P. Guralnik, Daniel E. Koditschek

Departmental Papers (ESE)

In this paper we introduce and study three new measures for efficient discriminative comparison of phylogenetic trees. The NNI navigation dissimilarity $d_{nav}$ counts the steps along a “combing” of the Nearest Neighbor Interchange (NNI) graph of binary hierarchies, providing an efficient approximation to the (NP-hard) NNI distance in terms of “edit length”. At the same time, a closed form formula for $d_{nav}$ presents it as a weighted count of pairwise incompatibilities between clusters, lending it the character of an edge dissimilarity measure as well. A relaxation of this formula to a simple count yields another measure on all ...