Altitude Control for Small Fixed-Wing Aircraft Using H∞ Loop-Shaping Method

Autopilot systems for UAVs without human pilots maintain the flight through an appropriate balance of aerodynamic forces autonomously. That is to say, they are used to make flight missions more reliable and efficient. Autopilot system design architecture conventionally contains two sections, inner and outer loops. Inner loop is the stabilizer and the outer loop can provide one of the additional motion controls (or all) such as speed, altitude, and heading hold. In this paper, H∞ Loop-shaping method is used to provide the stabilizer mode and the PID controller is used to control the altitude.