TWIN ROTOR MIMO SYSTEM
Murari Lal Garg
Under the guidance of
Dr. Jeevamma Jacob
PHASE - 1
• It is a laboratory set-up designed for control
experiments. In certain aspects its behaviour resembles that of
a twin-rotor helicopter.
• TRMS is driven by two D.C. motors
• Its two propellers are perpendicular to each other and joined
by a beam pivoted on its base that can rotate freely in
horizontal and vertical planes
• Joined beam can be moved by changing the input
• Voltage in order to control rotational speed of propellers
• It is equipped with a pendulum counterweight hanging from
• It possesses a strong coupling between main and tail rotor
• So in certain aspect, it resembles of a twin-rotor helicopter
• The system is modelled in terms of 2 DOF
dynamics using Newtonian mechanics.
• All the effective forces have to be considered.
• Modelling is classified as 2 part:
1. 1DOF (without coupling)–
I. Vertical part(main rotor)
II. Horizontal part(tail rotor)
2. 2DOF –
combination of both part with cross coupling
• MAIN ROTOR :
using Newton torque equation –
Response of the system with unit step input to main rotor and
unit impulse to tail rotor
Response of tail rotor to various inputs with different main rotor
Response of main rotor to different step input
• Output of system is obtained what is
• Settling time of main rotor is very high.
• Response of input to main rotor is highly non-
• There is significant effect of main rotor input
to tail rotor (cross coupling).
• With the zero input to the main rotor, the
system is stable at 0.9326rad .
•  Twin Rotor MIMO System 33-220 User Manual, 1998 (M/S Feedback
Instruments, Crowborough, UK).
•  Ahmad, S.M., Shaheed, M.H. Chipperfield, A.J and Tokhi, M.O.,
“Nonlinear modelling of a twin rotor MIMO system using radial basis
function networks ”, IEEE National Aerospace and Electronics Conference,
•  Ahmad, S.M., M.H. Chipperfield, A.J and Tokhi, M.O., “Dynamic
modelling and optimal control of a twin rotor MIMO system”, IEEE
National Aerospace and Electronics Conference, 2000.pp 391-398
•  Lu, T.W. , Wen , P. ,”Decoupling control of twin rotor MIMO system
using robust deadbeat control technique” , IET Control Theory Appl. , April
2008, Volume 2, Number 11, .pp 999-1007.
•  B. Kada, Y. Ghazzawi, “Robust PID Controller Design for an UAV Flight
Control System” Proceedings of the World Congress on Engineering and
Computer Science 2011 Vol II, WCECS 2011, October 19-21, 2011, San