Robust Control based on ADRC and DOBC for Small-Scale Helicopter

Abstract

Abstract This paper introduces and compares two robust control techniques estimating disturbances for small-scale unmanned helicopters: adaptive disturbance rejection control (ADRC) and disturbance observer based control (DOBC). The six-degree-of-freedom dynamics model of the unmanned helicopter includes modeling errors and uncertainties that degrade control performance. Furthermore, the external disturbance and complex internal coupling seriously affect the control stability of the small unmanned aerial vehicle (UAV), but this is difficult to be considered in advance for controller design. For this reason, ADRC and DOBC are designed using a minimum nominal model to compensate for internal uncertainties and external disturbances. Simulation results based on slalom maneuvers show that the proposed controller successfully compensates for disturbance and provides excellent performance compared to the case of using only the PID controller. Other than to unmanned helicopters, it is applicable to most dynamic systems that can be approximated as a double integrator system.