Controller design using fuzzy logic for a twin rotor MIMO system

The paper discusses the design of a fuzzy logic controller for a twin rotor MIMO system. The system has three degrees of freedom, but we have designed the controller for two degrees of freedom (DOF) only, i.e., travel and elevation. The controller is designed such that a change in one degree should have minimum effect on the other and overall the system should remain stable. We have designed two fuzzy logic controllers: one for travel control and one for elevation: both are designed in MATLAB and have Sugeno inference. For the twin rotor MIMO system, commonly known as the helicopter problem, many conventional controllers exist. Our controller's performance had to be better than, or at least equal to, their's. To test the controller on a practical system was not possible, therefore we used simulations to benchmark the performance of the fuzzy logic controller. The simulation results show that the system performance with a fuzzy logic controller is superior to the system performance with a conventional PID or LQR controller, over the whole range of operating conditions.