Author name cluster

Fred Rothganger

Possible papers associated with this exact author name in Arrow. This page groups case-insensitive exact name matches and is not a full identity disambiguation profile.

2 papers

1 author row

ICRA Conference 2003 Conference Paper

Capturing a convex object with three discs

Jeff Erickson 0001
Shripad Thite
Fred Rothganger
Jean Ponce

This paper addresses the problem of capturing an arbitrary convex object P in the plane with three congruent disc-shaped robots. Given two stationary robots in contact with P, we characterize the set of positions of a third robot that prevent P from escaping to infinity and show that the computation of this so-called capture region reduces to the resolution of a visibility problem. We present two algorithms for solving this problem and computing the capture region when P is a polygon and the robots are points (zero-radius discs). The first algorithm is exact and has polynomial-time complexity. The second one uses simple hidden-surface removal techniques from computer graphics to output an arbitrarily accurate approximation of the capture region; it has been implemented and examples are presented.

Details

IROS Conference 2001 Conference Paper

An implemented planner for manipulating a polygonal object in the plane with three disc-shaped mobile robots

Attawith Sudsang
Fred Rothganger
Jean Ponce

Presents an implementation of a planner that uses three disc-shaped robots to manipulate a polygonal object in the plane in the presence of obstacles. The approach is based on the computation of the maximal discs (maximal independent capture discs or MICaDs) where the robots can move independently while preventing the object from escaping their grasp. It has been shown that, in the absence of obstacles, it is always possible to bring a polygonal object from any configuration to any other one with robot motions constrained to lie in a set of overlapping MICaDs. This approach is generalized to the case where obstacles are present by decomposing the motion planning task into (1) the construction of a collision-free path for a modified form of the object, and (2) the execution of this path by a sequence of simultaneous and independent robot motions within overlapping MICaDs. The approach is guaranteed to work provided a collision free path exists for the modified form of the object. Experiments with Nomadic Scouts and a visual localization system are presented.

Details