eBug v1.0

Latest Version: 1.0
Release Date: October 30, 2000
Tolman's Schematic Sowbug and eBug (Emulated Sowbug)

   In 1939, Edward C. Tolman, a psychologist, introduced the concept of the schematic sowbug in his paper "Prediction of Vicarious Trial and Error by Means of the Schematic Sowbug" (Psychological Review). The schematic sowbug is based on Tolman's purposive behaviorism, and it is believed to be the first prototype in history that actually implemented a behavior-based architecture suitable for robotics. The schematic sowbug navigates the environment based on two types of vectors, orientation and progression, that are computed from the values of sensors perceiving stimuli. (For more details on Tolman's schematic sowbug, read this paper.)
   eBug is a program that can emulate Tolman's schematic sowbug both in simulation and on a real robot (ActivMedia Pioneer AT, etc.), and its source code is available from this site.

Tolman's Schematic Sowbug (1939) eBug (2000)
Figure reproduced from Tolman, E.C. Behavior and Psychological Man. University of California Press, 1951. An emulated schematic sowbug is approaching one of the stimuli in the eBug simulation.


  • "Implementing Tolman's Schematic Sowbug: Behavior-Based Robotics in the 1930's" (A paper that reintroduces Tolman's schematic sowbug and evaluates it using eBug - 913 KB [PDF])
  • README file for eBug (5.2 KB)
  • eBug v1.0 distribution (43.4 KB)
    Required operating system and support software: 
  • RedHat Linux 6.0 or higher
  • GNU gcc 2.91.66 (egcs 1.1.2) or higher
  • RedHat Motif 2.0 or LessTif 0.88.x
  • The distribution was tarred up and compressed with Gzip. Use "tar -xvzf ebug-1.0.tar.gz" to extract the content. The source code in the distribution is only for the simulation capability. To run eBug on a real robot, please read the README file.

All rights of eBug are reserved by Georgia Tech Research Corporation (GTRC). Please read the COPYRIGHT file in the distribution for more details. eBug is created solely for the academic purpose, and it is not supported nor maintained regularly. However, if you wish to contact the author, send email to Yoichiro Endo (endo‍@‍cc‍.‍gatech‍.‍edu)

Mobile Robot Laboratory, College of Computing
Georgia Institute of Technology
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