Active control of dynamic platforms

The control of a dynamic platform system for offshore operations in adverse weather conditions is discussed in this paper. The aim is to control the deck of the dynamic platform system to remain stationary irrespective of displacement-type base disturbances and force/ torque-type deck disturbances. Two control schemes based on the principle of invariance are described. Open-loop control, with drift cancellation, is implemented for the heave (vertical) motion, which is not always possible to obtain in practical systems. An experimental rig has been used to investigate and validate simulation results. Good simulation and experimental results have been obtained.