Deep-ocean mining vehicle system has not only coupled relationship between component systems, but also a variety of design requirements of each system to accomplish the specified multi-tasks. To meet the multi-objectives of the complex system, multidisciplinary design optimization (MDO) is performed. Metamodels such as kriging model and response surface model are employed to reduce computational costs for MDO and to facilitate the automation and integration of component systems in a design framework. After verifying accuracies of metamodels, metamodel-based MDO for deep-ocean mining vehicle system is formulated and performed. Finally, results and advantages of the proposed design methodology are discussed.
Recently, deep-ocean mining system has received growing recognition for development of plentiful marine mineral resources. It consists of mining vehicle system, transportation system, and mother station. The mining vehicle system is a self-propelled crawler equipped with collector, crusher and pumping unit. It collects mineral resources, especially manganese nodules, while traveling on cohesive soil of about 5000 meters deep-sea. Transportation system conveys the manganese nodule collected from the mining vehicle system to mother station through flexible hose and buffer, i.e. intermediate raising unit. Mother station stores the collected mineral resources and controls each subsystem with utility equipments. Among these systems, mining vehicle system is a core component because it actually undertakes to pick up manganese nodules. There are a variety of objectives and design constraints related to mining vehicle system. Collector is required to pick up manganese nodules efficiently regardless of size of manganese nodules. Crawler should travel reliably on soft coil of deep-ocean under consuming as small amounts of energy as possible. Frame supporting vehicle system must be strong and stiff enough to maintain the shape in pressures of approximately 500 bars of deep sea. Moreover, there is physical coupling between each part of the system.