A novel approach to the attitude stabilization structure for ducted-fan operative aerial robots: Finding improvements for modeling error and strong external transient disturbance

This research concerns a novel attitude stabilization structure for a ducted-fan aerial robot to work against modeling error and strong external transient disturbance, and it focuses on two main control targets: modeling error compensation, and the improvement of disturbance resistance along the rolling channel. For the first research objective, we proposed an adaptive nominal controller with the reconfigurable control law design based on the estimation of the modeling error found in the closed-loop. Results of simulations and corresponding flight tests verified that the proposed adaptive control structure is robust against both constant and time-varying modeling error. For the other research objective, a SAC (Stability Augmentation Control) structure was devised based on the CMG (Control Moment Gyroscope) theory in order to provide extra moment which effectively withstands the transient disturbance beyond the CDG (Critical Disturbance Gain). Furthermore, we studied the corresponding controller for the SAC via the SMC (sliding mode control) theory, while the working mechanism and performance of the SAC were verified through a specially devised prototype.