The second Unibot prototype is being assembled! Most mechanical parts are there and the electronics are being worked on. Next to the electronics, some hardware to perform independent system identification and controller testing in each direction is developed.
This prototype is a follow up of the first prototype that used an arm to stabilize in the lateral (side to side) plane. That principle is also known as the Acrobot. Professor Spong (University of Illinois at Urbana-Champaign) and others performed a lot of research on it. This prototype replaced the Acrobot principle by the Inertia Wheel Pendulum in the lateral direction. This greatly reduces the non-linearities in the system and it gets rid of non-minimum phase behavior.
As can be seen on the above picture, the mechanical structure is being assebled. The electronics are being worked on. Professor De Callafon is helping me out a lot on this part.