The paper is concerned with a dynamic positioning control for a semisubmersible platform model against external forces such as ocean current, wind and waves. A dynamic positioning system using thrusters is generally employed to control a given position. In such a control, it is difficult for thrusters to resist the wave frequency motion because the linear exciting force is very strong. The purpose of the control is to maintain a given position using thrusters that do not respond to this force in the wave frequency range. The problem was formulated in a framework of H(∞) control, and a controller was designed using a linear mathematical model obtained from nonlinear motion equations of the platform. Model tests were carried out and the designed controller performed well. Model experiments were conducted in oblique incident waves, and some successful results are shown.
|Number of pages||8|
|Journal||International Journal of Offshore and Polar Engineering|
|Publication status||Published - Sep 1 2000|
All Science Journal Classification (ASJC) codes
- Civil and Structural Engineering
- Ocean Engineering
- Mechanical Engineering