This paper presents a new approach to reactive control utilizing the output of an explicit path planner which considers terrain preferences. To demonstrate the concept, a wavefront propagation type of planner algorithm, Trulla, is integrated into a reactive framework and used as part of the overall architecture. Terrain preferences are represented as weights or costs which are considered in generating a near optimal path. The algorithm is demonstrated on the CSM Denning-Branch MRV4 mobile robot for three scenarios: navigation out of a box canyon, planning with terrain preferences, and opportunistic path improvement.

Mobile Robotics/Machine Perception Lab
Colorado School of Mines
Golden, Colorado 80401
(303) 273-3874

This work is sponsored in part by the CRA Distributed Mentoring Program for Women and the Colorado Space Grant Consortium

To see Trulla in action:

• Click here to see an Example Setup with our robot Clementine.
• Now, click here to see the Example Workspace for the same setup. The goal is denoted by an * and the obstacle is shaded completely black. Regions of difficult traversal are shaded by degree of difficulty. The planned paths are shown by arrows with circular heads.
• To read more about research involving Trulla, feel free to download the postscript version of An Explicit Path Planner to Facilitate Reactive Control and Terrain Preferences by Robin R. Murphy, Ken Hughes, and Eva Noll, 1996 IEEE International Conference on Robotics and Automation, April 22-29, 1996, Minneapolis, MN., vol. 3., pp. 2067--2072..
• To view the above paper page by page, select Pageview
• The use of Trulla as part of an investigation about replanning paths in general is found in: When to Explicitly Replan Paths for Autonomous Mobile Robot by Murphy, Marzilli, Hughes, submitted to ICRA97.

To Download your own copies (depending on your compiler):

Two versions of Trulla are available: Trulla 1.0 contains original Trulla Code, while Trulla 2.0 accounts for map-updating and replanning. Each directory of code also contains two *.man MSWord documentation files.

• Trulla version 1.0 source code for Borland compilers
• Trulla version 2.0 source code for Borland compilers
• Trulla version 1.0 source code for Watcom
• Trulla version 2.0 source code for Watcom

How To Get More Information:

• You can write or call the lab directly at the above address / phone number.
• Dr. Robin Murphy may be reached with email sent to rmurphy@mines.edu.
• David Hershberger, a graduate student in the lab, may be reached at dhershbe@mines.edu.