Multi-dimensional water sampling unmanned surface vehicle development and application

Although unmanned surface vehicles (USVs) have been repeatedly used in water environment monitoring, for the conventional water sampling missions of freshwater resources, which need to collect water samples from multi-depths and multi-fixed points in high frequency, there is still a big gap between the demands and status. In this paper, a multi-dimensional water sampling unmanned surface vehicle (WS-USV) is addressed, which is used to water sampling missions in the environment protection service. This WS-USV is mainly equipped with a navigation control system and a water sampling system, which is designed to execute the water sampling missions automatically in multiple positions and multiple depths. For reducing tracking error under the complex water environment disturbance, a kind of multi-waypoints guidance and tracking control strategy based on the line-of-sight method and Proportion Integration Differentiation control is used in the navigation system. In addition, two strategies to refine the water sampling missions, mainly including water sampling and recycling strategies are designed, which are all run by programmable software modules in the onboard computer system. In the real field experimental application, this WS-USV could traverse multiple sampling positions in order and accomplish the fully automatic water sampling process.