Comparative analysis of continuous sliding-modes control strategies for quad-rotor robust tracking

This paper presents a comparative analysis involving four Continuous Sliding-Modes Control (Continuous-SMC) algorithms and a robustified PID control for a Quad-Rotor that can be used to deal with the tracking problem under the influence of external disturbances and uncertainties only by means of the measurable positions and angles. Such an approach is composed of a Finite-Time Sliding-Mode Observer (FT-SMO), which estimates the full state and identifies some type of disturbances, and a robust control strategy for underactuated systems. Several real-time experimental tests are carried out on the Quad-Rotor QBall2 platform by Quanser^{\protect \protect \relax \special {t4ht=} under the influence of wind gusts and load disturbances. A quantitative comparison analysis is performed for all of the proposed controllers in order to illustrate their robustness properties.