Underwater robots

University of Maryland


  • Python
    • 15,000 SLOC
    • AI, GUI
  • C++
    • 50,000 SLOC

30 member team

What does Tortuga do?

  • Competes in competitions
  • Does not leak
  • Drives under water
  • see and move around obstacles
  • home on sounds


  • 6 thrusters
  • Pressure vessel with a Mac Mini, batteries, custom electronics
  • Runs Gentoo Linux
  • 4 hydrophones
  • Grabber used as a claw


  • Great flexibility and unit testing support
  • compact code
  • easy to learn - easy to get new members up to speed
  • stdlib and 3rd party support helped a lot

Unit Testing

  • No 3rd party library to install and manage


  • C++ integration
  • Boost.Python and Py++ are powerful, but complex
  • Overheard for wrappers is large in terms of dependencies, disk space, and compile time
  • Small bugs and compiler incompatibilities lead to fragile bindings


  • Inflexible nature gratly constrains concurrent system design
  • Forced the core of our software into C++
  • C++ calling back into python is especially likely to run afound of the GIL

GUI & Simulator

  • Done in wxPython & Python-Ogre

Dependency Management

  • Build things with a custom script


  • Dynamic languages are great fit for dynamics problems
  • Python is great for robots because of their dynamic nature
  • State.py is their AI library