The Maribot Vane is an autonomous sailing drone project that has been in the prototype testing phase for two years, developing a fully capable platform to aid in long-term ocean research projects. With longer voyages required for further development, a more reliable physical platform is a high priority of the next-generation design. This paper applies a multi-objective, Reliability-Based Design Optimization (RBDO) approach to minimize the system cost and the probability of failure under anticipated operational conditions. The results will inform designers of the new platform about their trade-offs between the cost and reliability objectives.
This paper presents the application of design optimization methods to the early design stage of an autonomous surface vessel, known as the Maribot Vane. The Maribot Vane is an autonomous sail-powered surface vessel that is under development at KTH, the Swedish Royal Institute of Technology, by the Maribot (Marine Robotics) Laboratory. The goal of the Maribot Vane project is to develop an Unmanned Surface Vehicle (USV) that will be able to sail in open seas for long periods of time, presenting oceanographic scientists with a more cost effective and efficient research platform. This requires both robustness and low net energy loss. To accomplish these goals, Maribot Vane uses a rigid wing sail, a wind rudder self-steering system, and alternative methods for energy generation. The current iteration, seen in Fig. 1, is comprised of a repurposed 2.4 mR (single handed racing sailboat) hull, and a hollow, rib-structured, composite wing sail. The rig is a free-rotating rigid wing fitted with a control flap mounted off the trailing edge.
The current test platform has allowed for the development of many novel components, such as the rotating sailing wing, and it has been successful in proving the energy efficiency and practicality needed for autonomous operations. To work with this platform the Maribot proprietary automation algorithms for vessel avoidance and navigation have been improved and extended, which was necessary as all previous autonomous projects developed at the Maribot laboratory have been underwater platforms.
