The twin-rotor system demonstrates the principles of a non-linear MIMO (multiple input, multiple output) system, with significant cross-coupling.
Its behavior resembles a helicopter, but the angle of attack of the rotors is fixed and the aerodynamic forces are controlled by varying the speeds of the motors. Significant cross-coupling is observed between the actions of the rotors, with each rotor influencing both angle positions.

Features:
Visually & technical interesting control problem.
Non-Linear model.
Excellent for demonstration laboratory work.
Excellent model for more advanced research work including designing your own control systems.