Optimal Controller Design for Twin Rotor MIMO System

Abstract

Twin Rotor MIMO system (TRMS) is considered as a prototype model of Helicopter. The aim of studying the TRMS model and designing the controller for controlling the response of TRMS is that it provides a platform for controlling the flight of Helicopter. In this work, the non-linear model of Twin Rotor MIMO system has been linearized and expressed in state space form. For controlling action a Linear Quadratic Gaussian (LQG) compensator has been designed for a multi input multi output Twin Rotor system. Two degree of freedom dynamic model involving Pitch and Yaw motion has been considered for controller design. The two stage design process consists of the design of an optimal Linear Quadratic Regulator followed by the design of an observer (Kalman filter) for estimating the non-accessible state variable from noisy output measurement. LQR parameter i.e. Q and R are varied randomly to get the desired response. Later an evolutionary optimization technique i.e. Bacterial Foraging Optimization (BFO) algorithm has been used for optimizing the Q and R parameter of Linear Quadratic Gaussian compensator. Simulation studies reveal the appropriateness of the proposed controller in meeting the desired specifications.