DESIGNING A CONTROL SYSTEM FOR THE AUTONOMOUS SMALL SCALE HELICOPTER

Abstract

Designing a control system for the autonomous small scale helicopter mainly consists of two parts. First, Identify the system model (Helicopter model) and the second part is designing the compensator. Modeling the helicopter can be achieved by either first principles modeling or black box modeling. Based on the Model obtained, different controlling techniques can be used to design a compensator to achieve stability. This thesis presents an easy and accurate method to design the control system for the autonomous small scale helicopter. The helicopter system is identified using experimental data (black box modeling) with the help of MATLAB system identification tool box. And then the compensator is designed by using the MATLAB control system tool box. Various controlling methods like PID (Proportional Integral and Derivative), LQG (Linear Quadratic Gaussian) and IMC (Internal Model Controller) are compared while tuning the system to achieve highstability. The stability of the system is measured by its step response. Finally the system is simulated and its functionality is verified in MATLAB simulink. Since this thesis is focusing on the stable hovering state of the helicopter, we developed a simulated control system for the swash plate of the helicopter. Swash plate is mainly responsible for the helicopter's dynamics in rotation about X body axis (Roll) and rotation about Y body axis (Pitch). So the control system is developed and simulated in order to control the roll and pitch angles of the helicopter. The results show that LQG method gives the better step response than IMC, PID methods.