Motion Control System Design for a Novel Water-Powered Aerial System for Firefighting with Flow-Regulating Actuators

Flying water-jet propulsion devices, such as jet boards, jet packs, and jet bikes, can execute complex flight maneuvers. However, they require the direct involvement of trained operators to control, and their applications are very limited. In this study, we design an effective controller for a novel water-powered aerial system that aims for autonomous firefighting missions, especially at or in bodies water. Unlike existing water-powered systems, an assembly of flow-regulating actuators is proposed to fully operate the system in three-dimensional space. The paper first formulates the system dynamics by coupled partial ordinary differential equations. Then, the nonlinear controller is designed to ensure the desired system motion and stability. The design takes distinct characteristics of the system, such as coupling, under actuation, and effects of the hose conveying the water, into consideration so that the system is stabilized and uniform ultimate boundedness is achieved. Computational studies in comparison with previous control methods validated the superiority and feasibility of the proposed control system.