Flight Control Design for Small-Scale Helicopter Using Disturbance-Observer-Based Backstepping

摘要

This Note introduced a composite control strategy (namely, disturbance-observer-based command filtered backstepping) for improved tracking control, as demonstrated for a small-scale helicopter. A novel disturbance observer was proposed to estimate the immeasurable flapping angles and the lumped force and moment disturbances simultaneously. The acquired estimates were incorporated in a command filtered backstepping baseline controller to improve the control performance. The global asymptotic stability of the closed-loop system was established through the cascaded system analysis using the input-to-state stability property. Simulation results showed that the proposed composite control strategy achieved better tracking performance and robustness against parameter uncertainties and wind disturbances. However, the more significant benefits of using the proposed composite controller are the improvement of control efficiency, the reduction of demand on actuators, and the enhancement of attitude stability.