Getting a robot to stand on two wheels without tipping over involves a challenging dance with the laws of physics. Self-balancing robots are a great way to get into control systems, sensor fusion, and embedded programming. This build by [mircemk] shows how to make one with just a few common components, an Arduino, and a bit of patience fine-tuning the PID controller.
At the heart of the bot is the MPU6050 – a combo accelerometer/gyroscope sensor that keeps track of tilt and movement. An Arduino Uno takes this data, runs it through a PID loop, and commands an L298N motor driver to adjust the speed and direction of two DC motors. The power comes from two Li-ion batteries feeding everything with enough juice to keep it upright. The rest of the magic lies in the tuning.
PID (Proportional-Integral-Derivative) control is what makes the robot stay balanced. Kp (proportional gain) determines how aggressively the motors respond to tilting. Kd (derivative gain) dampens oscillations, and Ki (integral gain) helps correct slow drifts. Set them wrong, and your bot either wobbles like a confused penguin or falls flat on its face. A good trick is to start with only Kp, then slowly add Kd and Ki until it stabilizes. Then don’t forget to calibrate your MPU6050; each sensor has unique offsets that need to be compensated in the code.
Once dialed in, the result is a robot that looks like it defies gravity. Whether you’re hacking it for fun, turning it into a segway-like ride, or using it as a learning tool, a balancing bot is a great way to sharpen your control system skills. For more inspiration, check out this earlier attempt from 2022, or these self-balancing robots (one with a little work) from a year before that. You can read up on [mircemk]’s project details here.
But why this lame PID instead of something like LQR?
Ardurobots with PID were exciting… in 2010.
Because it’s a high school graduation project. It’s basically “color by numbers” as engineering goes.
It’s still cool. You can always make one with lqr and submit it.
Looking at the other links and comments also, cookie cutter or been done before is fine, but until someone goes all the way through the project from start to working properly it is new to them and a learning experience. My first projects I did from start to delivery were very painful, but turned out to be very beneficial as I worked on more complex systems. So hats off to the person/team that put this one together and got it to running.
PS: I have seen articles showing two wheeled robots done without a micro computer (or any computer) –
This article reminded me of the tragic fate of Jimi Heselden.
https://www.bbc.com/news/uk-england-leeds-11416654
I saw Segway Scooters used for tour groups, they could move easily/quickly from one point to another – and also easy to see if someone in the group was lagging behind
I built one one once. It was a ‘kit’ though and had some ‘sample’ software to download to it. So not from the ground up, but you could certainly fine tune it or rewrite or whatever to not only balance but to travel as well. Add an RPI for smarts if desired. Still have it.