This video shows a game strategy using QTI sensors mounted on a 3-D printed scoop (Thingiverse thing #56016)
Name: Clear the Table
Objective: Find and push objects off of a low platform. The robot that pushes off the most objects in the least amount of time (up to 2 minutes) wins.
Challenges: Sensing the edge of the ring; using sensors to detect different kinds of objects; switching the robot between find-push-retreat modes; making a plow for the front of the robot; making the objects to push off the table; making the playing field platform.
About the Robots
- Use a Parallax Boe-Bot, ActivityBot, Shield-Bot or SumoBot chassis-based robot.
- Contestants in each match must use the same servos to keep top-speed-capability similar:
- Parallax Continuous Rotation servos powered with regulated 5 VDC
- Parallax High Speed servos powered with 7.5 VDC
- This challenge is for autonomous robots — no remote control devices!
- You can use any combination of sensors to your robot that you want, such as:
- IR emitter/receiver object detectors (included in the Boe-Bot style kits)
- Whisker sensors (included in the Boe-Bot style kits)
- QTI Line Follower kit (QTI sensors included in SumoBot kits)
- Ping))) Ultrasonic Distance Sensor and Mounting Bracket Kit
- Sharp IR Sensor kit
- 2-axis or 3-axis accelerometer
- Vibra-tab sensors
- Color sensors
- You can make a custom plow attachment for the front of your robot:
- It can be made of any material that does not damage the table or the objects.
- It can be up to 12 cm wide, 12 cm tall, and can stick out in front of the robot up to 6 cm.
- It can be incorporated into the robot’s sensor system.
- It cannot be motorized.
About the Playing Field
- The playing field is table is 77 cm round and at least 5 cm tall. The surface is hard and smooth with a black finish that does not reflect infrared light (such as matte paint, rubber, or vinyl). There is a white IR-reflective band around the edge of the top of the table, 2.5 cm wide.
- Eight objects are placed on the table for the robot to push off. A timekeeper places the objects on the table in a random arrangement before each round. See Game Variation Ideas below for object ideas.
About the Game
- The timekeeper marks the start and end of each round, recording how long each one lasts (up to 2 minutes).
- A player puts a robot anywhere on the table, and when the timekeeper says “Go” the player starts the robot and cannot touch it again until the round is over.
- The round ends when one of these three things happens:
- The robot pushes all of the objects off of the table.
- The robot falls off of the table and touches the surface below.
- The timekeeper indicates 2 minutes are up.
- 1 point given for each object pushed off of the table.
- In the case of a tie, the robot with the shorter round time wins.
- In the case of a tie of both score and time, hold a rematch until there is a clear winner.
Game Variation Ideas
- Easy game: Make the objects easy to detect — identical, white, smooth round cylinders with closed tops and bottoms, about 4 cm wide and 10 cm tall. If using empty bottles or cans wrapped in copier paper, try putting a few pebbles in them so there is a little weight to them.
- Hard game: Use a variety of objects with different physical properties that make them harder to detect — different shapes, sizes, materials, textures, colors, and weights. Try dark, fuzzy stuffed animals and open-ended tubes lying on their sides, for example.
- Second-chance game: Make the table very low, about 1 cm. Deduct 1 point from the score each time a robot goes over the edge of the table and touches the surface below, but do not stop the round — if it can get back on the table the round will continue. In this scenario, it might be useful to consider the color of the surface under the table.
- Table variations: Consider using a white table with a black edge. Or, consider a square table and the challenges presented by placing objects in the corners.