Design and Control for a Reaction Flywheel Balancing Cube

Abstract

The goal of this undergraduate final year project is to develop and construct a balancing cube, which is a cube structure that can jump up and balance on its edges or corners without the use of any external support. The cube has three reaction wheels on three perpendicular faces that help it jump up and balance. The main applied theory in this project is conservation of angular momentum. In the jump up process, the spinning wheels are brought to a halt by the brake system, and due to the law of conservation of angular momentum, the angular momentum of the wheel is transferred to the cube’s body, causing it to jump up. At the self-balancing position, an IMU sensor provides feedback, and the motor can apply a specific torque to counteract the gravitational torque and prevent the Cubli from turning over.


This final year project report focuses on the mechanical design and the application of the control systems in the project. The cube constructed in this project was able to jump and balance on its edges or corners. It is controlled by an LQR-controller and adaptive controller in MATLAB Simulink.

Demo of Reaction Flywheel Balancing Cube
Reference

[1] Gajamohan, M., Merz, M., Thommen, I., & D’Andrea, R. (2012, October). The cubli: A cube that can jump up and balance. In 2012 IEEE/RSJ International Conference on Intelligent Robots and Systems (pp. 3722-3727). IEEE. [pdf]