Integrating a wave-excited energy harvester into an unmanned surface vehicle: Design, numerical analysis and experimental tests.

Lacking a long-term power supply restricts the endurance of unmanned surface vehicles (USVs) and their application in remote sea areas. To address that ptoblem, a reliable solution based on the utilisation of wave energy is proposed in this study, where a wave-excited energy harvester is integrated into the USV. A fully coupled mathematical model is established to describe the dynamics and the electricity generation performance of the integrated system, considering the coupling of the mooring system. Numerical results given by this mathematical model are validated by physical experiments. The influence of the external load, the wave height, the wave period, the pendulum length, the pendulum mass and the mooring system on the system's performance are investigated, respectively. Experimental results of two small-scale prototypes, performed in a wave flume, show that the time-averaged generated electrical power is up to 324.89 mW when the wave height is 9.00 cm and the wave period is 1.72 s , where the corresponding wave-to-wire efficiency is 9.72%. Results indicate that the pendulum length, the pendulum mass, and the configuration of the mooring system significantly influence the resonant period and bandwidth. • A new wave-powered USV based on an inertial pendulum is proposed. • The proposed wave energy harvester has the capability to tune natural frequency. • A time-averaged electric power of 324.89 mW is achieved under a flume wave height of 9 cm. • The mooring system has a significant effect on the bandwidth of the USV. [ABSTRACT FROM AUTHOR]