The Robotics Institute

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Foundations of Robotics Seminar, December 6, 2011
Time and Place | Seminar Abstract



Probabilistically Complete Motion Planning with for Problems with Discrete Tasks, Hybrid Dynamivs, and Real-Time Constraints

Kris Hauser
School of Informatics and Computing

Indiana University at Bloomington

 

Time and Place

Tuesday, December 6, 2011
GHC 2109
Talk 4:30 pm

Abstract

 

Motion planning is an essential capability for enabling robots and virtual characters with many degrees of freedom to perform complex tasks. Early results in motion planning have shown that exact solution is computationally intractable, and hence researchers have settled for weaker notions of completeness. Under various assumptions, modern sample-based planners are known to achieve probabilistic completeness -- the property that the probability of finding a path, if one exists, asymptotically approaches 1 as more time is spent planning. Unfortunately, these assumptions are violated for problems that involve discrete sequences of tasks, hybrid dynamics (e.g., making or breaking contact), or when path computation and execution occur simultaneously in real-time. Hence, traditional sample-based planners do not work well, if at all. In this talk I will present three new general-purpose planning algorithms for these new settings: Multi-Modal-PRM (MMPRM), Random-MMP, and Adaptive Time Stepping with Exponential Backoff (ATS+EB). I prove that they are not only probabilistically complete, but exponentially convergent, which implies that the expectation and variance in running time is finite. Moreover, I present probabilistically complete methods for incorporating informed sampling strategies that make planning faster in practice without violating asymptotic completeness. I demonstrate the application of these algorithms to legged locomotion in rough terrain with NASA's six-legged ATHLETE robot, nonprehensile object manipulation with the Honda ASIMO, and assisted teleoperation of a high speed robot manipulator at IU.

 

Bio

 

Kris Hauser received his PhD in Computer Science from Stanford University in 2008, bachelor's degrees in Computer Science and Mathematics from UC Berkeley in 2003, and worked as a postdoctoral fellow at UC Berkeley.s Automation Lab. He has held his current position as Assistant Professor of Computer Science at Indiana University since 2009, where he directs the Intelligent Motion Lab. Research interests include algorithms for robot motion planning, integration of planning and perception, and semiautonomous robots. Applications of his research have included vehicle collision avoidance, robotic manipulation, robot-assisted medicine, and legged locomotion in rough terrain.

Website: http://www.cs.indiana.edu/~hauserk

 


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