Robotic Line Follower

As part of our course work for technology in 5th year, our class was entered into the Robotics Ireland Line Follower competition. In this competition, each student had to create a sumo robot, with its aim to travel around a previously chosen path as soon as possible. Once the robot starts to move it is timed until it completes the whole track. If the robot does not follow the designated line it is disqualified.

Aims

With the First Lego league, and sumo robot completed. I had a good understanding of how to design, manufacture and program a winning robot. I used the lessons i learnt previously to excel at this particular project. Like with the Sumo robot i started to design the robot on CAD. I looked at various past examples of winning robots to understand how they preformed so well. I incorporated some design ideas into my own. In CAD i played around with different sizes and looks, to create a robot that i was confident could work yet also proud of its appearance. I knew the line follower needed.

• Large wheels so it could move quickly across the track.

• Needed a large enough base to house the Genie Board, battery, motors and toggle switch.

• Needed two LDRs and a led at the front to know if the robots still remains on the line.

• I wanted the line follower to have a respectable appearance.

With these criteria in mind, and after multiple CAD design alterations, the following design was chosen.

Description

As with the Sumo robots i used the CnC to cut out all the pieces for the line follower. It took approximately one to two months to make, given that a few altercations had to be made. At the front of the robot, there is two LDRs and an LED as previously stated. The LEDs function is to cast light onto the track so that the LDRs can make out the black line more clearly. The LDRs and positioned on either side of the black line, if the left LDR notices the black line it will turn left, this will mean that the right LDR will be in contact with the line so this will turn the robot right. This zigzag motion of movement causes the robot to follow the line efficiently.. On top is the toggle switch to power the robot, and a spoiler just for appearance sake. Underneath the frame, the Genie E18 board is contained, along with the motors either side of it, to rotate the wheels. I created the wheels to be large to support the frame thus stopping the motors and board from dragging on the ground. Given the reduced number in parts this robot was quite easy to construct, this was beneficial as it meant i could spend more time on the code.

Problems

Thankfully, this project had less problems than the sumo robot. However, not ever thing went smoothly. There was complications with the wheels, firstly the holes for the motors to slot into were too big, often the wheels would fall off when on the track. Once this issue was fixed, the acrylic wheels were were sliding quite a bit on the plastic track. While the programming gave me less problems than before there were still ,many times were the robot would simply run off the track.

Result

To prepare us for the national competition, there was a class one was held. The line follower performed well and won the school competition. The national line follower competition took place at the same event in may. The days leading up the robot was working well, having consistently got around the track in good time, with only minor slip ups. In the national competition, I came first in both the oval track the difficult one.

Conclusion

The previous robots gave me the experience to know how to design, manufacture and program a functional robot. By investing time in producing a good detailed design, and focusing the majority of my time on the software aspect, i was able to produce a capable and reliable robot by the competitions deadline. This approach would help me with future projects.