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Tosun T.,GRASP Laboratory | Yim M.,GRASP Laboratory
Proceedings - IEEE International Conference on Robotics and Automation | Year: 2015

We address the problem of detecting embeddability of modular robots: namely, to decide automatically whether a given modular robot design can simulate the functionality of a seemingly different design. To that end, we introduce a novel graph representation for modular robots and formalize the notion of embedding through topological and kinematic conditions. Based on that, we develop an algorithm that decides embeddability when the two involved designs have tree topologies. Our algorithm performs two passes and involves dynamic programming and maximum cardinality matching. We demonstrate our approach on real modular robots and show that we can detect embeddability of complex designs efficiently. © 2015 IEEE. Source

Hebert M.,Carnegie Mellon University | Bagnell J.A.,Carnegie Mellon University | Bajracharya M.,Jet Propulsion Laboratory | Daniilidis K.,GRASP Laboratory | And 5 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012

Semantic perception involves naming objects and features in the scene, understanding the relations between them, and understanding the behaviors of agents, e.g., people, and their intent from sensor data. Semantic perception is a central component of future UGVs to provide representations which 1) can be used for higher-level reasoning and tactical behaviors, beyond the immediate needs of autonomous mobility, and 2) provide an intuitive description of the robot's environment in terms of semantic elements that can shared effectively with a human operator. In this paper, we summarize the main approaches that we are investigating in the RCTA as initial steps toward the development of perception systems for UGVs. © 2012 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE). Source

Ayanian N.,GRASP Laboratory | Kumar V.,GRASP Laboratory | Koditschek D.,GRASP Laboratory
Springer Tracts in Advanced Robotics | Year: 2011

We address the synthesis of controllers for groups of multi-robot systems that enable them to create desired labelled formations andmaintain those formations while travelling through an environmentwith obstacles, with constraints on communication. We assume that individuals in a group are capable of close coordination via high bandwidth communication, but coordination across groups must be limited because communication links are either sporadic or more expensive.We describe a method for developing feedback controllers that is entirely automatic, and provably correct by construction.We provide a framework with which navigation of multiple groups in environments with obstacles is possible. Our framework enables scaling to many groups of robots.While our paper mainly addresses groups of planar robots in ℝ2, the basic ideas are extensible to ℝ3. © 2011 Springer-Verlag. Source

Steager E.B.,Drexel University | Steager E.B.,GRASP Laboratory | Sakar M.S.,GRASP Laboratory | Kim D.H.,Drexel University | And 3 more authors.
Journal of Micromechanics and Microengineering | Year: 2011

One of the great challenges in microscale science and engineering is the independent manipulation of cells and man-made objects on the micron scale. For such work, motile microorganisms are integrated with engineered systems to construct microbiorobots (MBRs). MBRs are negative photosensitive epoxy (SU-8) microfabricated structures with typical feature sizes ranging from 1 to 100 νm coated with a monolayer of swarmer cells of the bacterium Serratia marcescens. The adherent cells naturally coordinate to propel the microstructures in fluidic environments. In this study, ultraviolet light is used to control rotational motion and direct current electric fields are used to control the two-dimensional movement of MBRs. They are steered in a fully automated fashion using computer-controlled visual servoing, used to transport and manipulate micron-sized objects, and employed as cell-based biosensors. This work is a step toward in vitro mechanical or chemical manipulation of cells as well as controlled assembly of microcomponents. © 2011 IOP Publishing Ltd. Source

Kushleyev A.,GRASP Laboratory | Mellinger D.,GRASP Laboratory | Powers C.,GRASP Laboratory | Kumar V.,GRASP Laboratory
Autonomous Robots | Year: 2013

We describe a prototype 75 g micro quadrotor with onboard attitude estimation and control that operates autonomously with an external localization system. The motivation for designing quadrotors at this scale comes from two observations. First, the agility of the robot increases with a reduction in size, a fact that is supported by experimental results in this paper. Second, smaller robots are able to operate in tight formations in constrained, indoor environments. We describe the hardware and software used to operate the vehicle as well our dynamic model. We also discuss the aerodynamics of vertical flight and the contribution of ground effect to the vehicle performance. Finally, we discuss architecture and algorithms to coordinate a team of these quadrotors, and provide experimental results for a team of 20 micro quadrotors. © 2013 Springer Science+Business Media New York. Source

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