Linearized Modelling and Control for a Twin Rotor System

Abstract

The focus of this paper is on the control design and simulation of twin rotor aero-dynamical system (TRAS). The challenges for control design in these systems lie in their nonlinearity and the inherent cross coupling between motion in the vertical and horizontal directions. Working from a highly nonlinear, dynamically coupled, mathematical model, controller design is presented for the angular position/velocity in vertical and horizontal planes of motion. Three linear control methods were developed and optimized to control the TRAS, namely full state feedback (FSF), linear quadratic regulator (LQR), and PID control. Simulation and experimental results show trade-off between these control methods. Although better performance was achieved with LQR, more effort was needed. The PID control has always proved to be a simple approach that works well with linear models. However, in this study case the performance was strongly affected by the coupling effect as demonstrated by simulation and experimental results