Design of PI?D? controller for robust flight control of a UAV using multi-objective bat algorithm

Nowadays there is a substantial increase in the use of UAVs in aerospace industries and several diverse applications like defense, disaster management, aerial photography, logistics, etc. and the diversity of applications is proliferating. But the non-linear & continuously time varying dynamics of these UAVs significantly affect the tracking of flight trajectory and thus the designed control system must fortify a robust behavior to the uncertainties and disturbances. This paper, employs the use of multi-objective variant of bat algorithm for the design of fractional order PID controller for the robust flight control of an unmanned aerial vehicle (UAV). The optimization function has been formulated as a mixed sensitivity problem for ensuring robust behavior. As per the results obtained in this paper, the designed FOPID controller ensures good tracking and robustness margins and thus ensure robust response in presence of uncertainties.