Pursuit-Evasion Problem

This research deals with the problem of computing the motions of one or more robot observers in order to maintain visibility of one or several moving targets. The targets are assumed to move unpredictably, and the distribution of obstacles in the workspace is assumed to be known in advance. Our algorithm computes a motion strategy by maximizing the shortest distance to escape ---the shortest distance the target needs to move in order to escape the observer's visibility region. Three main points are covered in this work: 1) The design and implementation of a reactive planner; 2) the integration and testing of such a planner in a robot system which includes perceptual and control capabilities; 3) The design and simulation of a motion planner for the task of maintaining visibility of two targets using two mobile observers.

Experiments


Target tracking in an environment with holes, the observer is the blue disc the target the red dot, the obstacles are shown in black and, the yellow cone is the perceived observer area


Target tracking in a map with thousand of vertices (a portion of the Louvre museum)

Multi-robot target tracking. The red observer start tracking the red target and the blue observer the blue target The shortest distance to escape is computed on the union of the observes visibility regions The best strategy to maintain targets visibility was to switch targets, there is not assignation between targets and observers


Target tracking with a real robot, the camera pointing to the ceiling is used to localize the robot using landmarks. I did this experiment during my postdoc at Stanford University

Links to similar research

  • Autonomous observer project at Stanford University
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    Rafael Murrieta
    Last modified: October 30 2002