Marine Systems for Offshore Applications
Cheng S. Chin
Journal of Marine Science: Research & Development
The marine environment plays a vital role in our ecosystem, economy and even our daily lives. As we increase our reliance on oceans for new resources and expanding civil, commercial and scientific activities, we are faced with a need for good marine systems capable of performing in this environment. Marine systems are usually used for a wide range of applications, such as exploring the extreme depths of our ocean, harvesting resources ranging from food to oil, monitoring our environment,
... ing national defence operations, transporting products and other subsea activities. While doing this, these systems operate in an environment with challenges such as high hydrostatic pressures, harmful interaction with electronics and materials and strong hydrodynamic forces. To tackle these problems, it is evitable to have some form of marine systems that is robust to these challenges. One of the areas that the marine systems face these challenges is performing a subsea vehicle control such as surface vessels and/ or Underwater Robotic Vehicles (URVs) in the harsh environments. Exploring and exploiting the deep oceans is a challenging, expensive and time-consuming activity. It is a complex environment in which vehicle control systems must not only avoid obstacles but also compensate for unpredictable disturbances, such as sea currents and the drag effects of umbilicals or riser, while compensating for uncertainties in position and orientation. One of the problems that many vehicles suffer from is that of tracking errors, which leads to an unnecessary extension of survey mission time and an increase in mission costs. Besides, the dynamic behaviors of the vehicle depend upon the configuration of the onboard sensors and equipment. In order to achieve the best performance, lowlevel controllers are required to adapt to a particular vehicle payload configuration. To develop, implement and test advanced control algorithms and fault-tolerant capabilities under realistic conditions, it is necessary to build an environment where rapid control prototyping and hardware-in-the-loop techniques can be used to aid in the design process as well as during the pre-implementation stage. Hence, the research agenda for marine system engineering is to reform and transform activities using intelligent techniques for vehicle's control systems design, systems integration, energy conversion, field monitoring and sensing, focusing on research and applications that are significant and impact in technical and economic performance. Some potential drivers are as follows: 1. There is an industry desire for new technologies that are smart or intelligent and fundamentally more reliable in operation. There is a need for research to develop new smart controls, intelligent inspection technologies and more reliable systems that emphasize overall system integrity in every environment to reduce cost exposure and risk. For example, the abovementioned technology using the URVs is necessary, especially where a more limited human interface is inevitable. 2. Research emphasis is directed towards future subsea developments and integrity of existing technologies, including applications for innovative and composite materials, smart controls, continuous condition monitoring, system diagnostics, wireless communications underwater, improved data transfer and data management, local subsea power generation, energy harvesting and autonomous operation. 3. Subsea field development is increasingly in deeper water, further offshore, in harsh environments. Research is needed to adapt and/or develop new technologies to facilitate such future developments in a cost-effective and technically efficient manner.