This research project was inspired by the observation that a normal two-wheeled self- balancing robot cannot explicitly handle situations when wheels ride over and slip on minor obstacles such as small rocks and projectiles, resulting in a lose of balance. 

This slipping is handled by calculating the friction force to detect slipping instance and use discrete controller to handle slipping separately.

This detection mechanism can also be used for off ground and touch down detection, which allows safer operation and handling of emergency situations.