Adaptive fuzzy backstepping control of flexible marine riser with uncertain parameters and input saturation constraint

Abstract

To suppress the vibration of a flexible riser system with input saturation and uncertain parameters under the influence of unknown external disturbances, an adaptive fuzzy backstepping boundary control algorithm was designed. First, the backstepping method and Lyapunov function are used to analyze the subsystem and design the virtual control law. On this basis, the adaptive fuzzy system was designed to approximate the unknown nonlinear term in the design process, and the smooth hyperbolic tangent function and the auxiliary system based on Nussbaum function were introduced to limit control input. The stability and uniform boundedness of the closed-loop control system are proved by the Lyapunov stability theory without simplifying or discretizing the infinite dimensional dynamic model. Finally, the effectiveness of the proposed control algorithm is verified by comparing the control effect with proportional–integral–derivative control and the previous adaptive backstepping control by MATLAB simulation. The simulation results show that the proposed control algorithm can overcome the uncertainty of system parameters and effectively suppress the riser vibration under input constraints, and its control effect is better than proportional–integral–derivative control and adaptive backstepping control.

Investigation on fatigue crack propagation failure mechanism of hydraulic lifting pipe in deep‐ocean natural gas hydrate exploitation

“…In recent years, some scholars have explored the study of riser vibration control, established corresponding control models, and formed more effective control methods. [35][36][37] In this study, by focusing on the problem of fatigue crack propagation failure of hydraulic lifting pipe for deep-ocean mining, a fatigue crack growth analysis methodology on the surface of hydraulic lifting pipe is established, which not only considers the multifield coupling effect between the ocean flow field, riser stress field, and internal flow field, but also considers the longitudinal and transverse coupling nonlinearity of the riser, the induced nonlinearity of the ocean current, and the flow-induced nonlinearity of the internal flow field. Meanwhile, the fatigue corrosion crack propagation test of high-strength 13Cr-L80 riser material is carried out.…”

“…Fu et al 34 introduce the collision factor between risers into the reliability analysis of risers and provide an approach for estimating the failure probability of riser collision by considering these joint effects and their stochastic nature. In recent years, some scholars have explored the study of riser vibration control, established corresponding control models, and formed more effective control methods 35–37 …”

Dual extended state observer–based prescribed performance control of output-constrained hydraulic-driven barrel pitching servo system

“…Adaptive technology is an effective approach to address parameter uncertainties. 13,14 By integrating the adaptive technique into the backstepping control, Ahn et al 15 and Yao et al 16,17 separately improved the position-tracking performance of the pump-controlled EHSS and valve controlled EHSS.…”