Boundary robust adaptive anti-saturation control of vibrating flexible riser systems

• Published in: Ocean engineering 2019-05, Vol.179, p.298-306
• Main Authors: Zhao, Zhijia, He, Xiuyu, Wen, Guilin
• Format: Article
• Language: English
• Subjects: Boundary control; Disturbance adaption; Flexible risers; Input saturation; Vibration control
• ISSN: 0029-8018; 1873-5258
• DOI: 10.1016/j.oceaneng.2019.01.020

In this paper, we address the vibration abatement problem of a flexible riser system preceded by nonlinear input saturation characteristic and uncertainties of the system. By virtue of Lyapunov theory, auxiliary system and robust control strategy, a boundary robust adaptive anti-saturation control is developed to restrain the vibration, remove the nonlinear input saturation effects and compensate for the uncertainties of system parameters and boundary disturbance. Applying the rigorous analysis without simplifying or discretizing the partial differential equation dynamics, the controlled system is ensured to be uniformly bounded stable with the designed control law. In the end, simulation results are presented for control performance verification. •A boundary robust adaptive anti-saturation control is presented to suppress the riser's vibration.•The online updating laws are developed to compensate the uncertainties of system.•The auxiliary system is introduced to handle the input saturation.•The σ-modification is exploited to adjust the robustness of the system.•The stability of the closed-loop system is proved via rigorous Lyapunov analysis.