Control of an unmanned coaxial helicopter using hybrid fuzzy-PID controllers

In this paper a hybrid control system for a novel small scale coaxial helicopter is presented. Based on a cascade architecture the control system is made up of an inner-loop, for attitude control, and an outer-loop, for trajectory control. The inner-loop consists of three PID controllers for the roll and pitch angles, and altitude control. The outer-loop generates the reference signals for the inner-loop and is based on two fuzzy controllers that provide a viable way of including human flight experience into the control system. Simulation results, for hovering and non-aggressive flight, demonstrate that the proposed controller is very promising.