Dynamic Obstacle Avoidance Demo

Radu Bogdan Rusu of TU München and Ioan Alexandru Sucan of Rice University have been working hard at Willow Garage the past several weeks as part of our winter internship program. One of their projects was to do dynamic obstacle avoidance (replanning) with a 7-DOF PR2 prototype arm using real-time 3D mapping coupled with sampling-based motion planning. Radu's 3D perception pipeline processes the data received from the Hokuyo laser sensor in real-time, with continuous map updates every 20-50ms. This map is sent to Ioan's sampling-based motion planning pipeline, which monitors the execution of the current plan. If the current path is no longer valid, a new one is computed. If no safe path is found, the arm is stopped until a safe path can be computed. Computation of a new path usually takes 10-100 ms, depending on the density of the map.

In the video, the PR2's task is to move its 7-DOF arm from left to right, changing its goal every 10 seconds -- it tries to go left for 10 seconds, then it tries to go right for 10 seconds.