Trajectory Tracking of a 3-DOF Helicopter by LQR Based PID Controller

Abstract

Linear Quadratic Regulator (LQR) technique has been known to provide optimal controlled feedback to improve closed-loop stability of process-control systems. In this article attitude control problem has been investigated for a 3-Degree of Freedom (3-DOF) benchmark laboratory system involving high nonlinearities, parametric uncertainties and strong inter-axis couplings. This article describes the 3DOF helicopter system's mathematical model and then illustrates an approach to formulate the controller design.A simple approach has been explainedto obtain PIDtuning parameters from matrix that has gain values of the LQR controller. The controller design simulation results show that the control technique which has been investigated provides static and dynamic performance over multipoint operations, therefore providing better closed-loop stability and responsive control for the 3-DOF helicopter system in comparison to conventional PID control algorithms.