Class #7: Probabilistic Roadmaps (2/3) –
            Sampling Strategies





The Gaussian strategy (left) is intended to place milestones mostly near the obstacle boundary. The Bridge test (center) is aimed at producing a higher density of milestones in narrow passages. The visibility-based connection strategy (two figures on the right) is aimed at building coarser roadmaps, still with good coverage and connectivity properties.

  • Topics
    - Multi-query vs. single-query sampling
    Sampling vs. connection strategies
    - Multi-stage sampling
    - Obstacle-sensitive sampling
    - Narrow-passage sampling
    - Diffusion strategies
    - Delayed collision checking
    - Visibility-based connection
  • Required Readings:
    • Obstacle-sensitive and narrow-passage sampling:
      V. Boor, M.H. Overmars, A.F. van der Stappen. The Gaussian sampling strategy for probabilistic roadmap planners. Proceedings of the IEEE International Conference on Robotics and Automation, pp. 1018-1023, 1999 [pdf].
      D. Hsu, T. Jiang, J. Reif, and Z. Sun. The Bridge Test for Sampling Narrow Passages with Probabilistic Roadmap Planners. Proceedings of the IEEE International Conference on Robotics and Automation, Taipei, 2003. [pdf]
    • Reduction of roadmap size (visibility-based connection):
      T. Siméon, J.P Laumond, and C. Nissoux. Visibility-Based Probabilistic Roadmaps for Motion Planning. Advanced Robotics J., 14(6), 2000 [ps] [pdf].

  • Additional Readings:
    • Another obstacle-sensitive sampling technique:
      N.M. Amato, O.B. Bayazit, L.K. Dale, C. Jones, D. Vallejo. OBPRM: An Obstacle-Based PRM for 3D Workspaces. Proc. Workshop on Algorithmic Foundations of Robotics (WAFR'98), March 1998, pp. 155-168. [pdf]

  • Powerpoint slides:

o       Introduction

o       Paper 1

o       Paper 2