Multi variable self tuning PID control of a Twin Rotor MIMO system

An attempt is being made to design a new multivariable self tuning PID (Proportional-Integral-Derivative) controller (STC) for pitch angle and yaw angle control of the main and tail rotor of the Twin Rotor MIMO System (TRMS) under parametric uncertainty and external disturbance. The PID parameters are updated in real time based on relationship between PID and minimum variance control (MVC). The TRMS model is identified based on an on-line auto regressive moving average (ARMAX) model whose parameters are tuned by a recursive least square (RLS) algorithm. The results obtained show superiority of the proposed controller with respect to a fixed gain PID controller under external disturbances.