Almost two years ago, in February 2023, I embarked on a journey without knowing how deep the water was. At first, it just looked like a small pond, so I jumped in. Two and a half years later, I am still rowing, and I don’t know how long this voyage will last. This story is about one of my most significant projects. I am moving with a gardener mindset rather than an architect mindset. I have in my mind where I wanna finish, but I don’t know how to get there. I am learning and planting as I go.
We live in a world where Self-Driving Cars are available in the commercial market.
Yet, I am dedicating all my energy and resources to a Line Follower Bot. At
its core, every Self-Driving Car or Autonomous Vehicle is just a simple line
follower, but the line they follow is not so simple. Autonomous Vehicles
plan their own trajectory, and while traversing, their main goal is to minimise
the deviation from that trajectory. For Line Follower
Competitions, the trajectory is laid out on an arena. A white line (2.5cm to
3cm thick) on a black surface or a black line on a white surface. All it gotta do is
just follow the path laid out. How hard can that be?
Wish it were that simple. First things first, being able to
see the path. Mostly, people use multiple IR sensors to detect white and black.
Some models also use reflective capacitive sensors, but there is not much difference in how they work. Multiple sensors form an array-like arrangement to calculate the
position of the line. More sensors will give you better resolution of
the position of the line. Still, you are limited by your processor’s ability to accommodate how
many sensors it can handle, and more sensors will require more
electrical and computational power.
The sensors calculate the line’s position. Your Error will be, Error = Calculated
Position – Desired Position. All the control algorithms work on the
Error, where you are and where you want to be.
No more technical details, otherwise this will be a
long-long blog. So I made a line follower in 2k23, a beginner line follower, more to say. I named her LIANA (Technical Jargon – Line Follower Arduino
Nano), after Lyanna Stark, the most beautiful woman in Westeros. It outperformed many at the competition. Though it had a lot of bugs, somehow
the bugs turned into features at the arena, and it got through 50% of the maze.
But I was nowhere near winning, and I wanted to win a competition no matter how long
it took. I have the patience and dedication for it (I know people who have
been working on line follower bots for 11 years).
Fast forward to 2k24, I made another line follower, LIANA II. Better than my first line follower, more sensors, better resolution, better
motors, better motor driver and everything. Performance was much better than
LIANA I, as expected. On the day of the competition, I calibrated LIANA II for over an hour on the test track, until it got to the edge of
following the line perfectly. Everything was ready, though I hadn’t slept much
in the previous nights, I was confident. Seeing the arena, it looked like a
piece of cake, just waiting there for me to grab it. And guess what happened on
the actual track? It didn’t move a bit when I placed it on the track.
Turns out, all the testing and tunning I did on the test tracks really sucked
all the battery it had. And so bright I am that I didn’t even think about
charging it before putting it on the tracks. As per the rules of most line follower competitions, once you place your bot on the track, you aren’t allowed to touch it again. And sadly, that was the end of it.
LIANA II was excellent; it worked perfectly again when I recharged the batteries, but that was in my room. At this point, I started to suspect that LIANA has Stage Fright. Whatever, far from giving up. After 1 month of this LIANA II fiasco, I started working on LIANA III. The development of LIANA III, the funding support, building it up, and its performance in the World Robotics Championship 2024 is a long story, so I want to cover it in another blog dedicated to LIANA III.
This Project is very near to my heart because I have spent countless days and nights working on it. I have often worked continuously for 12 hours without taking any breaks besides water. It has taught me so many things regarding technology and failure that my entire career is built on what Liana taught me.
Below are a few Photos of LIANA II. Sadly, I had already dismantled LIANA I before taking any images.
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