Quad-Rotor Robust Tracking: A Continuous Sliding-Mode Control Strategy

The design of robust tracking control for Quad-Rotors is an important and challenging problem nowadays. In this paper a robust tracking output-control strategy is proposed for a Quad-Rotor under the influence of external disturbances and uncertainties. Such a strategy is composed of a Finite-Time Sliding-Mode Observer (FT-SMO) which estimates the full state from the measurable output and identifies some type of disturbances; and also of a combination between PID controllers and a Continuous Sliding-Modes Controller (Continuous-SMC), that exponentially robustly track a desired time-varying trajectory and despite the influence of external disturbances and uncertainties. The closed-loop stability is provided based on Input-to-State Stability (ISS) and Finite-Time ISS (FT-ISS) properties. Finally, some experimental results in real-time show the performance of the proposed control strategy.