Tesla has been promising full self-driving capabilities for almost a decade now and they still haven’t pulled it off. YouTube is brimming with videos of Waymo self-driving cars committing hilarious blunders. My Mazda’s lane-keeping system gets confused by merging roads. It turns out that autonomous driving is difficult — and yet, children around the world build robots for $20 that manage it just fine. That gave Austin Blake the brilliant idea to build a “self-driving” cart that makes use of groundbreaking line-following technology.
Line-follower robots are very popular projects for robotics beginners. Simple kits cost less than an Andrew and small children can build them with minimal adult supervision. Once completed, they can drive along “roads” quite reliably without any need for direct human control.
That all works because a line on the ground, in a contrasting color, is really easy to detect with affordable hardware. Typically, the line is black and goes on a floor of a lighter color (like white). An infrared sensor can “see” the difference between the black and the white. With two of those sensors straddling the line, the robot can correct its course if it starts to move away from the line. It is driving itself! At least if you’re being generous with semantics.
Blake’s cart works the same way. He has attempted to build more sophisticated self-driving vehicles in the past, but with mixed success. This rudimentary line-following tech is much easier to implement and much more reliable. Compared to a small line-follower robot, it really only has three major differences: more infrared sensors, a different steering setup, and a much bigger size — big enough to carry a full-grown man. Like Blake, for example.
The final version of the cart has 32 infrared sensors connected to an Arduino Mega Pro Mini development board. The large number of sensors makes the line-following more reliable and covers a greater area, which makes sense for a cart of this size. Blake made a custom PCB to hold all of those, like a massive Arduino shield.
Because this is the same cart from his last video, which has a steering wheel actuated by a motor, Blake kept most of the original hardware. That included the Arduino Nano that controls the steering motor.
That worked well and the cart is able to drive itself around Blake’s shop without endangering anyone. It was even able to cross over line intersections, which is traditionally a challenge for line-followers. Maybe Tesla should get in touch with Blake and finally roll out that self-driving capability they’ve been promising.