Cable angle feedback control for helicopter slung load system using delayed feedback

Abstract

In recent years, a large number of small-size helicopters are used for some industrial works. In this study, we focus on vibration control for a small-size helicopter with slung load system. We employed delayed feedback control to suppress vibration of the load by measuring the cable angle. We verified the effectiveness of the vibration control method by real flight tests. As for the controller design, it is difficult to determine the delayed feedback parameters because the method is nonlinear control. We demonstrate a way to design the controller considering the rotational dynamics and the translational dynamics whose system parameters were identified by the frequency response test. We built a simple planar model like a double pendulum and the delayed feedback controller was designed by root locus of the system. The optimum delayed feedback parameters derived theoretically are nearly the same as the parameter determined by trial-and-error in experiment.