Reentry control system design for a riser pipe experimental model under steady current

The paper is concerned with a reentry control problem of moving a riser pipe hanged off and positioning its lower end just above a target. The difficulty of the manual control motivates us to design an automatic control system for dynamic reentry in current. A motion equation of a riser pipe model in current is derived via modal analysis. Then LQI (Linear Quadratic with Integral action) control methodology is applied to obtain an appropriate reentry controller by means of HILS approach. Experimental successful results on reentry control are shown.