Sliding mode based roll control law design for a research UAV and its flight validation

Research unmanned air vehicles (UAVs) provide a cost effective solution for rapid development and testing of new algorithms in real system flight testing. The sliding mode control architecture is applied by the authors to the lateral dynamics of scaled YAK-54 UAV. Flight dynamic analysis and control system design is complicated by the problem of uncertain measurements, external disturbances and modeling uncertainties. Using the powerful tools of sliding mode theory we present an innovative robust lateral control algorithm. For robust stabilization of lateral dynamics, 1
^st
-order sliding mode control was designed. Due to its limitation of chattering in the control channel and extra information demand, a 2
^nd
-order super twisting algorithm was designed to provide chattering free improved robust control. The designed framework's effectiveness is tested by applying the developed scheme on scaled YAK-54 UAV. The results of the flight tests are included in the paper to demonstrate the benefits of the adopted framework for the control design and further it focuses on bridging the gap between theory and experimental practice.