Adaptive Control of a Flexible Riser System

An adaptive boundary controller is developed in this article for minimizing the vibration displacement of a flexible riser. The dynamics of riser system is represented by partial-ordinary differential equations. Through combining boundary control, adaptive technique with backstepping technique, an adaptive boundary controller is given for realizing vibration restraint for the riser system, where an adaptive law is developed for coping with parametric uncertainties and a signum function is introduced for mitigating the boundary disturbance. With the designed adaptive boundary controller, the spillover instability can be successfully avoided. Finally, simulations are displayed to explain that the given controller is valid to realize vibration restraint of a flexible riser.