No abstract

In this paper, a framework for guidance, navigation and control of marine vehicles is proposed. The focus is on application of unmanned surface vehicle for performing high accuracy measuring tasks. The desired maneuvering path is defined as a combination of standard path sections and delivered to the guidance system. The measurements are filtered and the unmeasurable states are estimated in navigation system and fed back to the guidance and control systems. An extended Kalman filter based approach is used in navigation system, in order to take the nonlinear behaviors of the system into consideration. The proposed control scheme is a modular system consisting of a cascade structure, where the unified inner loop is responsible for velocity control and the outer loop can be adapted independently to various missions. The model parameters are estimated based on subspace identification method using data obtained from a measuring vehicle, MESSIN. The results have been further used for design of control and navigation systems. The performance and effectiveness of the proposed framework are demonstrated on a model for a path following mission.

An innovative, satellite-guided search-and-rescue-system will be presented. This system utilises an autonomous rescue vessel to retrieve overboard personnel. The system acts instantaneously, which significantly increases the chance of survival. It was developed for use on special ships or offshore platforms, where workers are subject to adverse weather conditions and overboard personnel are often discovered too late. A substantial challenge is the automation of the autonomously acting rescue vehicle as well as its integration into the superior search-and-rescue-process. To ensure the fastest possible approach to the casualty without endangering the person, a cascaded control concept has been designed. Two-degree-of-freedom control concepts are used to separate the tracking performance from the disturbance rejection. The inner speed control structure is divided into two parts and consists of the control structure itself with an in-line allocation to the device configuration. The contribution mainly addresses the automation of the rescue vessel, the synthesis of the control system of the autonomously acting vehicle as well as the integration into the superior search-and-rescue-process. Finally, some test results of this complex system are shown.