Automated Survey in Very Shallow Water using an Unmanned Surface Vehicle ?

摘要

The paper describes a combined survey campaign using an unmanned surface vehicle and integrating a side scan sonar and two magnetometers in a gradiometer set-up in very shallow water of the coastal transition zone from land to water. For the survey several areas have to be covered to provide an unexploded ordnance clearance for identifying places suitable for positioning of a jack-up barge needed for a subsequent offshore drilling campaign. Next to the limited water depth the necessary small line spacing especially for the magnetometer measurements were challenging. In that way, the paper discusses the adaptation of the necessary modules for guidance, navigation and control of the vehicle to run the survey campaign with a reliable coverage of the measurement area. Therefore, methods and applications are presented used for path planning, straight line path following, sensor integration and fusion as well as vehicle motion control. Further, the paper describes the connection between the modules to establish the entire closed system. In addition, the paper gives an overview about the requirements the survey campaign and the specified instrumentation as well as the resulting vehicle set-up. Especially the unconventional installation of the magnetometers was essential for the measurements in very shallow water. The paper finishes with results of the side scan sonar and magnetometer measurements and discusses the motion control process with regard to the survey requirements.