Lab 10: Robot Exchange

Presentation: PPT - PDF

Challenge Statement:

A team of two robots must enter an exchange zone, exchange a golf ball, and exit the environment.


  1. Teams are comprised of one handyboard and one NXT group.
  2. One team member (Robot A) starts with a golf ball.
  3. The world has 4 entrances; each robot will start in a different randomly chosen entrance. The teams will be notified of the entrance they will be using right before the run.
  4. The robots must exchange the golf ball in the center "exchange area".
  5. Both robots must exit the environment through any entrance.
  6. Robot B must exit with the golf ball.
  7. The golf ball cannot touch the ground during any part of the run.
  8. The robots must complete the task autonomously.
  9. All runs will be timed from the time the robots start to the time the last robot leaves the environment.

The Environment & The Robot:

  1. The exchange area will have walls perpendicular to the border but not extending into the center area. These walls will be less than 1in wide and 2in tall.
  2. The exchange area will have a border marked by tape that will be visible to the robot's light sensors.
  3. The robot must be no larger than 8in x 8in x 8in.


Blocks are 6 x 6 inches


  1. The NXT and the handyboard kits are equipped with infrared sensors that can detect the exchange area's tape.
  2. The handyboards can locate the NXT robots by applying some concepts from the Braitenberg lab.
  3. Path planning can be useful to enter and exit the environment.
  4. If path planning fails, wall following might be of use.


Each robot receives an individual grade for entering and exiting the environment. Three attempts will be allowed with a combined maximum of 10 minutes.

  1. Robot reaches the exchange area - 20 points
  2. Robots exchange the golf ball :
      i) Failed exchange - 35 points
      ii) Successful exchange - 70 points
  3. Robot exits the environment - 10 points


The fastest group that completes the task wins the competition. The winners will receive 100% on the final exam.

Grading Sheet : Lab 10

Last Updated : 4/16/09 by Victor Marmol
(c) 1999-2009: Howie Choset, Carnegie Mellon