Finite time disturbance observer-based adaptive composite control for disturbed unmanned helicopter.

In this paper, a composite control scheme integrating finite time disturbance observer (FTDO) and adaptive control is presented to solve the trajectory tracking issues of unmanned helicopters with matched and mismatched disturbances. Firstly, an FTDO is employed to accurately estimate the disturbance information within finite time, thereby mitigating the impact of lumped disturbances on the helicopter system and enhancing the anti-disturbance capability of the control scheme. Subsequently, the disturbance compensation term is incorporated into the controller, and a data-driven adaptive proportional-derivative (APD) controller is designed to track the desired signals of yaw angle and position. The introduction of the adaptive mechanism enables real-time parameter adjustment based on system data, effectively eliminating parameter deviations, improving control accuracy, and enhancing the adaptability of controller in complex environments. In addition, the disturbance estimation error is embedded into the closed-loop stability analysis, and the system stability is rigorously demonstrated using Lyapunov theory. Finally, simulation experiments compare the proposed method with improved active disturbance rejection control (ADRC) and FTDO-based continuous terminal sliding mode control (CTSMC). The results demonstrate that the proposed scheme achieves strong robustness and high control accuracy even in the presence of both matched and mismatched disturbances.