Gapped & Crossed Line Following. Part 3. Strategy and Robot
We list the number of decisions that the robot is making while following the line. Then, we group them and decide on the number of sensors to be used.
- #206
- 20 Jan 2016
FIRST LEGO League (FLL) is the most popular LEGO Mindstorms Robotics Competition. Each year the season starts in Augusts and completes by May. We've created a lot of resources for FIRST LEGO League to help teams prepared, learn and have fun. Here are most of the tutorials, building instructions and courses for FLL
Here we collect resources that are common for most LEGO Mindstorms robotics competitions. The resources here could be used for FLL, WRO, general line following, sumo and many more.
Learn how to build LEGO robots and win the FIRST LEGO League competition.
Using LEGO Mindstorms EV3 and NXT robotics kits we give curriculum ideas, share professional experience and teach students to think and develop as engineers. The goal of this category is to group specific examples from specific missions.
Contains resources for LEGO Mindstorms competitions. There are many LEGO competitions using EV3, NXT and RCX robots. These competitions have some similarities, but could be quite different in general. Most popular are of course FIRST LEGO League and World Robotics Olympiad.
We list the number of decisions that the robot is making while following the line. Then, we group them and decide on the number of sensors to be used.
We follow a line. We start from the Smooth Proportional Line Following program and modify it a little for this program. We follow the line with the middle sensor attached on port 2.
It's inevitable. While following this gapped line we would reach a gap. The robot must somehow understand that there is a gap and must make a decision on what to do. For detecting the gap we use the Rotation Sensor. Not the most popular, but very convenient in many cases. Check out the video.
We've detected the gap. It's time to move over it. This is difficult because we have to detect where the line is after the 0.1 meters gap on the line following field.
Next important state is Turn Right with our robot. This happens when we detect a line on the right.
Next state in our state machine programming pattern is the "Turn Left" state and the corresponding behaviour.
We can Turn Right. We can Turn Left. How do we decide which way to go if there are lines both to the left and to the right. Check out the video.
All worked as expected, up until know because the robot got lost. This happens when we turn right and the line does not continue to the right. Now the robot must somehow understand that it is "lost" and escape.
We discuss the state of "Lost" and the different ways we could escape this state. We also build the next step of our State machine programming pattern where the next state is determined by the previous state.
The final video from the course. The robot escapes the state where it is lost. This happens if it can not continue in any direction.