#Robotics Line Rescue Additional Considerations

David Meego - Click for blog homepageJust when I thought I had finished the series of articles explaining the techniques need to complete the Robocup Junior Australia Line Rescue Challenge, I realised that there were some additional considerations and advice that will help take your robots to the next level.

The idea of this article is not to provide solutions, but to make teams aware of issues and problems they make encounter, so they can make their hardware and software more robust and capable.

Good Luck.

The article has been divided into sections to help organise the points:

Robot Build

  • Make sure your robot can easily pass through the archway with space to spare. It is possible robot might not be dead straight as it tries to get through the archway. Remember if you fail to get through the archway, you will get no points for the round.
  • Make sure that all the cables are tucked in, routed internally or cabled tied to ensure they don’t catch on the archway or other obstacles.
  • Make sure your build is robust and has a low centre of gravity so it will not break or fall over.

Line Following

  • Your robot should be able to handle reverse colour line following, black tile with white line.
  • Your robot should be able to handle slopes including curves and intersections on slopes.
  • Your robot should use grippy tyres or tracks and clean them as they will get dirty and lose grip.
  • Your robot should be able to handle debris up to 3mm high on the course.
  • Your robot should be able to handle height changes in tiles up to 10mm.
  • Add code to look for other primary colours which might be used for challenge tiles.
  • Check light readings for every new venue and/or time of day, if needed.


  • Make sure you can handle cross roads (intersections with not green markers), so just continue forward.


  • Make sure you check twice for obstacle if using touch sensor to avoid false detection when falling forward over see-saw.
  • When moving around obstacles don’t go too wide in case the tile is raised.
  • Obstacles might not be on a straight section of line


  • Make sure you move forward and check for green after see silver to be sure you in are in rescue zone. This avoids false silvers on speed bumps.
  • Your robot can back up against the silver strip to straighten itself to compensate when it enters the rescue zone at an angle.
  • Your robot can use a gyroscope sensor to help with rescue. It can be used to help exist the spill zone by knowing the robot’s orientation. It can also be use to vary the ultrasonic distance based on the angle so that it can “look into” the corners.
  • For Open: Decide if you are going rescue all cans or scan for black cans. Your robot can use another colour sensor to look for black cans and not to rescue them.


  • You can use a Multiplexer to have more sensor ports. The EV3 Sensor Multiplexer for EV3 or NXT is available from mindsensors.com.
  • Play the game. Use the drop zone and work in both directions to get the maximum number of points for tiles you can do while allowing you bypass tiles you might fail on.
  • Be prepared to make changes on the competition days to be able to complete challenge tiles.
  • Make sure you start a journal when you first start building your robot and keep a diary of what you do. Keep pictures of your robot. Record changes you make and why. Record readings you take.
  • Only make one change at a time and test its effects before moving to the next change.
  • Keep multiple backups of your journal and your programs (including MyBlocks which are stored separately for NXT).
  • Keep previous versions of your programs so you can roll back if needed.
  • Make sure you have fully charged your battery and have a spare charged battery.

I hope these points help you make your robots awesome.

Note: This article will be updated as I think of new points worth mentioning, so it will be worth checking back every now and then.

More Information

For more information on robotics and the EV3 Basic extensions to Microsoft Small Basic, check out the following links:

Hope you find this information useful.


This article was originally posted on http://www.winthropdc.com/blog.

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