Aircraft detection Antennas Disturbance observer Finite-time convergence Finite-time tracking control Manipulators Navigation Non-singular terminal sliding mode controls Non-singular terminal sliding modes Observer-based Quad rotors Quadrotor unmanned aerial vehicles Robot applications Sliding mode control Tracking control approach Unmanned aerial vehicles (UAV) Wind perturbations disturbance observer finite-time convergence non-singular terminal sliding mode quadrotor unmanned aerial vehicle wind perturbation