Paper Title
Autonomous Four Rotor Helicopter Control Strategy Using Pitch and Roll Movement Control Alternately

Abstract
In the present study, autonomous four rotor helicopter movement control strategy using pitch and roll movement control alternately was proposed, and the autonomous flight test evaluation was performed. To realize over 50 m long distance flight of the drone under unstable GPS signal situations such as under the bridge or inside tunnels for the periodic inspection, the improvement of the control method is important for the stable control. The aim of this study is to compare three control strategies - simple PD control, boundary condition and using pitch and roll movement control alternately strategy in over 50 m range autonomous four helicopter movement. By comparing the standard deviation (S.D.) from the central orbit divided by the moving distance, a proposed control method using not pitch and roll movement control simultaneously and a control method using boundary condition of both sides represents high performance against general optimized P-D control. The proposed pitch and roll movement control alternately realized small value of 56 % and its S.D. of evaluation function comparing with the optimized P-D only control. Our proposed method would be effective in the situation that there is no skilled the drone control operator and the flight by visual confirmation of man are hard conditions. Keywords - Control Strategy, Examination Four Rotor Helicopter, No Gps Signal