Experimental studies of a disturbance observer for attitude control of a quad-rotor system

This paper presents a simple design of a disturbance observer (DOB) for a quad-rotor system. To achieve robust attitude control of a quad-rotor system against disturbance, DOB is employed. Based on the conventional DOB structure, a proposal of simple modification allows an efficiency of calculation for estimating the disturbance term. The proposed DOB does not require the delayed calculation so that efforts of designing Q filter can be minimized. The effectiveness of the proposed DOB is evaluated through experimental studies of attitude control of a quad-rotor system.