Cascade Control of Active Heave Compensation Nonlinear System for Marine Crane

During the rough marine environment, heave compensation is used to offset motion of vessel when a crane lifts and lands load. Thus, load are realized decoupled. In previous studies, interference items such as hydraulic cylinder friction, underwater drag force nonlinear friction in active system compensated concentrated be estimated. this paper, we disassembled items; disturbance observer adaptive rate designed estimate unmodeled uncertain parameters, respectively; an compensator with cascade controller which has (DOB-ANCC). For displacement, paper derived control law model based on backstepping method. The outer loop displacement inner pressure control. simulation verifies effectiveness strategy proposed availability for hoisting efficiency (DOB-ANCC) can reach more than 95%, maximum tracking error ± 0.035 m.