Fixed Wing Unmanned Aerial Vehicle (UAV) Control Systems Design using Robust Guaranteed Cost Control Based PID Controller

Abstract

An airplane has six degrees of freedom—three on lateral directions and three on longitudinal directions—while flying which inherently has unstable flight behaviors. In order to stabilize the flight of unmanned aerial vehicles (UAVs), automatic flight control should be implemented continuously. In designing automatic control of UAVs, the major problem is the mathematical model of the UAV always has uncertainties. This paper proposes a Robust PID controller based on Guaranteed Cost Control (GCC) method to control the flying of UAV. This method is the extension of Linear Quadratic Regulator (LQR) optimal control method by adding uncertainty factor to the Algebraic Riccati Equation. The solution of this Robust Control method is a state feedback matrix consists of the parameters of the PID control (Kp, Ki, and Kd). The proposed robust PID controller is then simulated to the UAV pitch control system using SIMULINK® with the nominal model and the bounded model that contains uncertainty. The result of the simulation shows the GCC method give the faster response and settling time, less offset and stabilizes the bounded model compared with the LQR.