Document Type : Original Article
Today, robots and unmanned aerial vehicles are being used extensively in modern societies. Due to a wide range of applications, it has attracted much attention among scientists over the past decades. This paper deals with the problem of the stability of a four-rotor flying robot called quadrotor, which is an under-actuated system, in the presence of operator or sensor failures. The dynamical model of quadrotor is expressed in terms of different physical phenomena by the Newton-Euler method. Subsequently, a back stepping control approach has been developed, considering actuator and sensor failures. The stability analysis based on the Lyapanov method shows that the designed control strategy maintains the stability of quadrotor closed loop dynamics even in the presence of failures. The simulations of the control system indicate that the proposed control strategy is capable of maintaining performance and maintains system stability in the event of a failure of the operator or sensor.