Lego Balancing Act by Chris, Don

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Lego Balancing Act by Chris, Don Kris

• Alma College
• NSF Mindstorm Workshop
• June 2005

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Overview

• Processor cooperation to accomplish a task
• Compensate for unreliable communication
• Reinforce basic mechanics

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Problem A Balancing Act (1)

• Construct a see saw to be populated with 3 bots
• 2 servant bots assigned to opposite ends of the
  see-saw each attached to a cog rail to permit
  forward and backwards movement only each has a
  storage area to hold weights
• 1 control bot in the center attached to the pivot
  point via a rotation sensor

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Problem A Balancing Act (2)

• Control bot determines whether the see-saw is
  perfectly balanced. If not, sends a message to a
  servant bot to move either forward or backwards.
  Servant bot may receive messages with lt 100
  reliability (natural and/or artificially
  controlled unreliability)

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Problem A Balancing Act (3)

• Task Levels (all using pre-built system)
• Easiest Give all communication routines, unequal
  weights
• Hardest Handle variable starting positions,
  movable fulcrum, no provided code

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Problem Alternate version

• Control bot stationary on one end with moving
  counter balance bot on other end.
• Counter balance bot moves in response to requests
  from control bot.
• Control bot is moving up and down burning
  building saving people (light sensor detects
  floors of building each as a black line)

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Save me!