INTEGRAL COMPENSATION FOR DISTURBANCE REJECTION IN LONGITUDINAL FLIGHT CONTROL OF A FIXED-WING UNMANNED AERIAL SYSTEM

摘要

Longitudinal flight control plays a high relevance role for conventional and unmanned aircraft due to its importance in take-off, climbing, cruise, descent, and landing phases of the flight cycle, where the elevator deflection works as the main control input. For that reason, an automatic controller is necessary for providing flight stability to these Unmanned Aerial Systems (UAS) against wind external disturbances. In the literature, several disturbance-estimation mechanisms have been proposed in control of diverse linear and nonlinear systems. In this work, an Integral Compensation Based-Control approach is introduced for pitch control of the fixed-wing UAS-S4 Ecatl. The proposed robust scheme allows both suitable rejection of matched external disturbances and reference tracking tasks. Also, in order to deal with the effect of high-gain of the controller an anti-windup saturation is adequately implemented for the control input. It is worth to note the main advantage of the introduced control approach, is that implementation of an observer is unnecessary for disturbance estimation. The satisfactory performance of the proposed robust controller is assessed in several numerical simulations. Here, the results show that the controller is capable to properly carry out trajectory tracking tasks even in presence of matched disturbances.