Design and Experiments of Angular Motion Control for a Novel Unmanned Water-Powered Aerial Vehicle

Manned water-powered aerial vehicles have been widely applied in the entertainment field. By leveraging an abundant water source, these exhibit great potential for implementation in various fields, especially in high-risk environments such as rescue and firefighting operations. However, their maneuverability depends entirely on the riders’ skills. Therefore, this paper proposes a novel unmanned water-powered aerial vehicle (UWAV) along with an angular motion controller for it. The proposed UWAV utilizes a nozzle rotation mechanism to adjust the water thrust’s direction and replace the role of the rider in governing the system’s motion. This study first derives a detailed mathematical model to describe its angular motion. Subsequently, a robust controller consists of two main components. The first part is a disturbance estimator formulated by an extended state observer (ESO), which estimates and compensates for disturbances in the control effort. The second part is an integral super-twisting sliding mode control (ISTSMC) law that incorporates the system’s rotational dynamic characteristics and ensures the system’s stability and robust tracking. Experiments are conducted to validate the proposed system through two scenarios: following step-like and sinusoidal references. The results demonstrated the feasibility of the design and the superiority of the proposed controller. Specifically, the control system achieves 56.98% lower root mean square error and requires 22.72% less control effort compared to that of the standalone ISTSMC.