Theoretical and experimental investigation of unmanned boat electric propulsion system with PMDC motor and waterjet

The use of unmanned marine vehicles has greatly increased in recent years. Unmanned surface boats with electric propulsion must possess power management capabilities in order to minimise the risk of propulsion power loss while the vessel is performing a certain task. The investigation of the electric propulsion system, prior to its integration onboard an unmanned boat, is the subject of this work. It includes a theoretical part, which focuses on the analysis and performance assessment of the propulsion motor; however the assessment is not complete until both motor and propulsion devices are tested experimentally in a specifically built facility. In this sense, a method for the analysis of permanent-magnet dc motors is given in conjunction with the development of a testbed for thrust and torque curve acquisition of power trains, including motor and waterjet. Speed and load control of the propulsion system is achieved through pulse width modulation, which appears a promising and simple technique for efficient control of dc propulsion systems. Finally, the control system implementation is visited, because it is considered an essential component of both the power management and propulsion systems of any unmanned boat.