Active control of a flexible marine riser system

In this paper, active control for vibration reduction of a flexible marine riser is studied by using boundary control, adaptive control and Lyapunov´s synthesis method. To achieve more accurate and practical dynamic behavior of the riser, the effects of time-varying internal fluid are considered in dynamics model of the riser. The signum function and adaptive boundary control scheme are design to compensate for the system parametric uncertainties. With the proposed control, the uniform boundedness and closed-looped stability is demonstrated via Lyapunov´s direct method. Simulation results illustrate the effectiveness of the proposed control scheme.