A self balancing two-wheel robot that wobbles, hence the name WobblyBot.
- Quite possibly the simplest design for a robot that could (sort of) balance itself on two wheels, without the use of accelerometer, gyroscope or microcontroller.
A great weekend project, and do check out the video to see it in action. And why Domo Kun? Because I think it's cute :) You can pretty much change the WobblyBot into any character you like.
Visit here for more build photos and tips.
How It Works
The robot is essentially a simple pendulum, with the pivot at the wheel axle. The bottom part of the robot’s body is significantly heavier than the upper part of it. This serves as a counter weight, keeping the entire body upright, hence the balancing act.
Step 1: Putting Things Together
The length of the cradle is really up to your choosing, but the width is design to fit a D sized battery holder with ease. The exact placement of the batteries are critical since it doubles up as the counterweight for the robot.
The batteries must be placed dead center, length-wise and width-wise. If not the robot will either not able to balance straight up, or it will not be able to move straight forward and backward (because one wheel is carrying more load than the other).
DC Geared Motors used are rated at 12V, 100mA, 130RPM and 58.8mN.m torque. The motor are driven at half the power (around 5.5V and 50mA). I’ll explain why later.
DC Geared Motors are used instead of the a normal DC Motors. They are better suited for this project due to the fact that it produces low RPM, and have enough torque to drive the robot. You will later find out that the robot could end up becoming quite heavy.
The motors are mounted directly to the cradle, note that there are room underneath the motor, this is the space where we will add more counter weight if need be.
The circuit that drives the motors is mounted on top of the batteries. I initially planned to make my own circuits before laziness strikes and end up hacking an RC Car for the circuit :)