OBSERVER-BASED ATTITUDE CONTROL FOR A TWO-ROTOR AERODYNAMICAL SYSTEM
In this paper, an attitude tracking control based on adaptive super twisting algorithm (ASTA) for a Two-Rotor Aerodynamical System is presented. Since the rotor blades present ﬁxed angle of attack, the system is controlled by varying angular rotor speeds, which
introduces highly nonlinear strongly coupled dynamics. Furthermore, taking into account the difﬁculty of measuring some of its states, and in order to implement the ASTA control, a Nonlinear Extended State Observer (NESO) is employed to estimate the vector state and furthermore unmeasured dynamics. This scheme increases robustness against non modeled dynamics and external disturbance, reducing modeling difﬁculties due to the fact that it is not necessary to know all the parameters of the system. Furthermore, an analysis of stability is provided, where sufﬁcient conditions are given in order to guarantee the stability of the closed-loop system. Experimental results demonstrate the feasibility of the control scheme and illustrate its
performance under external disturbance.